Document:

EX-10.1

 Exhibit 10.1 

SUMMIT MATERIALS HOLDINGS L.P. 

FOURTH AMENDED AND RESTATED 

LIMITED PARTNERSHIP AGREEMENT 

Dated as of [            ], 2015 

 
  

 
 THE LIMITED PARTNER INTERESTS (THE
“UNITS”) OF SUMMIT MATERIALS HOLDINGS L.P. (THE “PARTNERSHIP”) HAVE NOT BEEN REGISTERED UNDER THE U.S. SECURITIES ACT OF 1933, AS AMENDED (THE “SECURITIES ACT”), THE SECURITIES
LAWS OF ANY STATE, PROVINCE OR ANY OTHER APPLICABLE SECURITIES LAWS AND MAY ONLY BE SOLD IN RELIANCE UPON EXEMPTIONS FROM THE REGISTRATION REQUIREMENTS OF THE SECURITIES ACT AND SUCH LAWS. SUCH UNITS MUST BE ACQUIRED FOR INVESTMENT ONLY AND MAY NOT
BE OFFERED FOR SALE, PLEDGED, HYPOTHECATED, SOLD, ASSIGNED OR TRANSFERRED AT ANY TIME EXCEPT IN COMPLIANCE WITH (I) THE SECURITIES ACT, ANY APPLICABLE SECURITIES LAWS OF ANY STATE OR PROVINCE, AND ANY OTHER APPLICABLE SECURITIES LAWS; (II) THE
TERMS AND CONDITIONS OF THIS FOURTH AMENDED AND RESTATED LIMITED PARTNERSHIP AGREEMENT (THE “PARTNERSHIP AGREEMENT”); AND (III) ANY OTHER TERMS AND CONDITIONS AGREED TO IN WRITING BETWEEN THE GENERAL PARTNER AND THE
APPLICABLE LIMITED PARTNER. THE UNITS MAY NOT BE TRANSFERRED OF RECORD EXCEPT IN COMPLIANCE WITH SUCH LAWS, THIS PARTNERSHIP AGREEMENT AND ANY OTHER TERMS AND CONDITIONS AGREED TO IN WRITING BY THE GENERAL PARTNER AND THE APPLICABLE LIMITED PARTNER.
THEREFORE, PURCHASERS AND OTHER TRANSFEREES OF SUCH UNITS WILL BE REQUIRED TO BEAR THE RISK OF THEIR INVESTMENT OR ACQUISITION FOR AN INDEFINITE PERIOD OF TIME. 

 Table of Contents 

 

									
	 ARTICLE I DEFINITIONS
	  	 	2	  
		 	 Section 1.01.
	  	Definitions	  	 	2	  
	 ARTICLE II FORMATION, TERM, PURPOSE AND POWERS
	  	 	9	  
		 	 Section 2.01.
	  	Formation	  	 	9	  
		 	 Section 2.02.
	  	Name	  	 	10	  
		 	 Section 2.03.
	  	Term	  	 	10	  
		 	 Section 2.04.
	  	Offices	  	 	10	  
		 	 Section 2.05.
	  	Agent for Service of Process; Existence and Good Standing; Foreign Qualification	  	 	10	  
		 	 Section 2.06.
	  	Business Purpose	  	 	10	  
		 	 Section 2.07.
	  	Powers of the Partnership	  	 	11	  
		 	 Section 2.08.
	  	Partners; Admission of New Partners	  	 	11	  
		 	 Section 2.09.
	  	Withdrawal	  	 	11	  
		 	 Section 2.10.
	  	Investment Representations of Partners	  	 	11	  
	 ARTICLE III MANAGEMENT
	  	 	12	  
		 	 Section 3.01.
	  	General Partner	  	 	12	  
		 	 Section 3.02.
	  	Compensation	  	 	12	  
		 	 Section 3.03.
	  	Expenses	  	 	12	  
		 	 Section 3.04.
	  	Officers	  	 	13	  
		 	 Section 3.05.
	  	Authority of Partners	  	 	13	  
		 	 Section 3.06.
	  	Action by Written Consent or Ratification	  	 	14	  
	 ARTICLE IV DISTRIBUTIONS
	  	 	14	  
		 	 Section 4.01.
	  	Distributions	  	 	14	  
		 	 Section 4.02.
	  	Liquidation Distribution	  	 	15	  
		 	 Section 4.03.
	  	Limitations on Distribution	  	 	15	  
	 ARTICLE V CAPITAL CONTRIBUTIONS; CAPITAL ACCOUNTS; TAX ALLOCATIONS; TAX MATTERS
	  	 	15	  
		 	 Section 5.01.
	  	Initial Capital Contributions	  	 	15	  
		 	 Section 5.02.
	  	No Additional Capital Contributions	  	 	15	  
		 	 Section 5.03.
	  	Capital Accounts	  	 	15	  
		 	 Section 5.04.
	  	Allocations of Profits and Losses	  	 	16	  
		 	 Section 5.05.
	  	Special Allocations	  	 	16	  
		 	 Section 5.06.
	  	Tax Allocations	  	 	17	  

  
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		 	 Section 5.07.
	  	Tax Advances	  	 	17	  
		 	 Section 5.08.
	  	Tax Matters	  	 	18	  
		 	 Section 5.09.
	  	Other Allocation Provisions	  	 	18	  
	 ARTICLE VI BOOKS AND RECORDS; REPORTS
	  	 	18	  
		 	 Section 6.01.
	  	Books and Records	  	 	18	  
	 ARTICLE VII PARTNERSHIP UNITS
	  	 	19	  
		 	 Section 7.01.
	  	Units	  	 	19	  
		 	 Section 7.02.
	  	Reclassification of Interests	  	 	20	  
		 	 Section 7.03.
	  	Register; Certificates; Legends	  	 	20	  
		 	 Section 7.04.
	  	Registered Partners	  	 	21	  
	 ARTICLE VIII VESTING; FORFEITURE OF INTERESTS; TRANSFER RESTRICTIONS
	  	 	21	  
		 	 Section 8.01.
	  	Vesting of Unvested Units	  	 	21	  
		 	 Section 8.02.
	  	Forfeiture of Units	  	 	21	  
		 	 Section 8.03.
	  	Limited Partner Transfers	  	 	22	  
		 	 Section 8.04.
	  	Mandatory Exchanges	  	 	23	  
		 	 Section 8.05.
	  	Encumbrances	  	 	23	  
		 	 Section 8.06.
	  	Further Restrictions	  	 	23	  
		 	 Section 8.07.
	  	Rights of Assignees	  	 	24	  
		 	 Section 8.08.
	  	Admissions, Withdrawals and Removals	  	 	25	  
		 	 Section 8.09.
	  	Admission of Assignees as Substitute Limited Partners	  	 	25	  
		 	 Section 8.10.
	  	Withdrawal and Removal of Limited Partners	  	 	25	  
	 ARTICLE IX DISSOLUTION, LIQUIDATION AND TERMINATION
	  	 	26	  
		 	 Section 9.01.
	  	No Dissolution	  	 	26	  
		 	 Section 9.02.
	  	Events Causing Dissolution	  	 	26	  
		 	 Section 9.03.
	  	Distribution upon Dissolution	  	 	27	  
		 	 Section 9.04.
	  	Time for Liquidation	  	 	27	  
		 	 Section 9.05.
	  	Termination	  	 	27	  
		 	 Section 9.06.
	  	Claims of the Partners	  	 	27	  
		 	 Section 9.07.
	  	Survival of Certain Provisions	  	 	28	  
	 ARTICLE X LIABILITY AND INDEMNIFICATION
	  	 	28	  
		 	 Section 10.01.
	  	Liability of Partners	  	 	28	  
		 	 Section 10.02.
	  	Indemnification	  	 	29	  
	 ARTICLE XI MISCELLANEOUS
	  	 	31	  
		 	 Section 11.01.
	  	Severability	  	 	31	  

  
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		 	 Section 11.02.
	  	Notices	  	 	32	  
		 	 Section 11.03.
	  	Cumulative Remedies	  	 	33	  
		 	 Section 11.04.
	  	Binding Effect	  	 	33	  
		 	 Section 11.05.
	  	Interpretation	  	 	33	  
		 	 Section 11.06.
	  	Counterparts	  	 	33	  
		 	 Section 11.07.
	  	Further Assurances	  	 	34	  
		 	 Section 11.08.
	  	Entire Agreement	  	 	34	  
		 	 Section 11.09.
	  	Governing Law	  	 	34	  
		 	 Section 11.10.
	  	Submission to Jurisdiction; Waiver of Jury Trial	  	 	34	  
		 	 Section 11.11.
	  	Expenses	  	 	35	  
		 	 Section 11.12.
	  	Amendments and Waivers	  	 	35	  
		 	 Section 11.13.
	  	No Third Party Beneficiaries	  	 	36	  
		 	 Section 11.14.
	  	Headings	  	 	36	  
		 	 Section 11.15.
	  	Power of Attorney	  	 	36	  
		 	 Section 11.16.
	  	Separate Agreements; Schedules	  	 	37	  
		 	 Section 11.17.
	  	Partnership Status	  	 	37	  
		 	 Section 11.18.
	  	Delivery by Facsimile or Email	  	 	37	  
		 	 Section 11.19.
	  	Non-Occurrence of IPO	  	 	37	  

  
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 FOURTH AMENDED AND RESTATED 

LIMITED PARTNERSHIP AGREEMENT OF 

SUMMIT MATERIALS HOLDINGS L.P. 

This FOURTH AMENDED AND RESTATED LIMITED PARTNERSHIP AGREEMENT (this “Agreement”) of Summit Materials Holdings L.P.
(the “Partnership”), is dated as of [            ], 2015 (the “Effective Date”) and is by and between Summit Materials Holdings GP, Ltd., a
Cayman Islands exempted company (“Pre-existing GP”), as the General Partner pending consummation of the IPO (as defined in the IPO Reorganization Agreement referred to below), Summit Owner Holdco LLC, a Delaware limited
liability company, as the prospective interim General Partner upon consummation of the IPO, Summit Materials, Inc., a Delaware corporation (“IPO Corp”), as the prospective General Partner immediately after Summit Owner Holdco
becomes such interim General Partner, and the Limited Partners whose names are set forth in the books and records of the Partnership. 

BACKGROUND 
 1. The
Partnership was registered on July 29, 2009 as an exempted limited partnership pursuant to the provisions of the Exempted Limited Partnership Law (2007 Revision) of the Cayman Islands. 

2. The Initial Exempted Limited Partnership Agreement of the Partnership, dated as of July 29, 2009, was amended and restated on
July 30, 2009 and January 29, 2010. 
 3. The Partnership was domesticated as a limited partnership under the laws of the State of
Delaware pursuant to Section 17-215 of the Act by (i) filing a Certificate of De-Registration with the Registrar of Exempted Limited Partnerships, Cayman Islands, on December 23, 2013, (ii) filing a Certificate of
Limited Partnership Domestication in the office of the Secretary of State of the State of Delaware on December 23, 2013, (iii) filing a Certificate of Limited Partnership in the office of the Secretary of State of the State of
Delaware on December 23, 2013 (as it may be amended from time to time, the “Certificate”), and (iv) executing the Third Amended and Restated Limited Partnership Agreement of the Partnership, dated as of
December 23, 2013 (the “Original Agreement”). 
 4. Pursuant to the IPO Reorganization Agreement effective
as of [            ], 2015 (the “IPO Reorganization Agreement”), the Partners under the Original Agreement have agreed that, on the date of pricing the IPO,
(i) all outstanding interests in the Partnership will be converted into Class A Units (as defined below) in accordance with the IPO Reorganization Agreement, (ii) the Original Agreement will be amended and restated in the form of this
Agreement and (iii) the Partnership will be continued without dissolution. 
 5. The IPO Reorganization Agreement also contemplates
that, pursuant to the Contribution and Purchase Agreement dated as of December 18, 2014 (the “CCC Agreement”), in connection with the closing of the IPO, the Pre-existing GP will be replaced as the general partner of the
Partnership by Summit Owner Holdco LLC, immediately after which IPO Corp will replace Summit Owner Holdco LLC as the general partner of the Partnership. 

  
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 6. The pricing of the IPO of IPO Corp has occurred, as a result of which this Agreement has
become effective. 
 ARTICLE I 

DEFINITIONS 
 Section
1.01. Definitions. Capitalized terms used herein without definition have the following meanings (such meanings being equally applicable to both the singular and plural form of the terms defined): 

“Act” means, the Delaware Revised Uniform Limited Partnership Act, 6 Del. C. Section 17-101, et
seq., as it may be amended or supplemented from time to time and any successor thereto. 
 “Adjusted Capital
Account Balance” means, with respect to each Partner, the balance in such Partner’s Capital Account adjusted (i) by taking into account the adjustments, allocations and distributions described in Treasury Regulations Sections
1.704-1(b)(2)(ii)(d)(4), (5) and (6); and (ii) by adding to such balance such Partner’s share of Partner Minimum Gain and Partner Nonrecourse Debt Minimum Gain, determined pursuant to Treasury Regulations Sections 1.704-2(g) and
1.704-2(i)(5), any amounts such Partner is obligated to restore pursuant to any provision of this Agreement or by applicable Law. The foregoing definition of Adjusted Capital Account Balance is intended to comply with the provisions of Treasury
Regulations Section 1.704-1(b)(2)(ii)(d) and shall be interpreted consistently therewith. 

“Affiliate” means, with respect to a specified Person, any other Person that directly, or indirectly
through one or more intermediaries, Controls, is Controlled by, or is under common Control with, such specified Person. 

“Agreement” has the meaning set forth in the preamble of this Agreement. 

“Assignee” has the meaning set forth in Section 8.07 hereof. 

“Assumed Tax Rate” means the highest effective marginal combined rate of U.S. federal, state and local
income taxes (including, without limitation, taxes imposed under Sections 1401 or 1411 of the Code) for a Fiscal Year prescribed for an individual or corporate resident in New York, New York (not taking into account the deductibility of state and
local income taxes for U.S. federal income tax purposes). For the avoidance of doubt, the Assumed Tax Rate shall be the same for all Partners. 

“Available Cash” means, with respect to any fiscal period, the amount of cash on hand which the General
Partner, in its sole discretion, deems available for distribution to the Partners, taking into account all debts, liabilities and obligations of the Partnership then due and amounts which the General Partner, in its sole discretion, deems necessary
to expend or retain for working capital or to place into reserves for customary and usual claims with respect to the Partnership’s operations. 

  
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 “Award Agreement” means any award agreement entered into
by the Partnership with a Service Provider to whom the Partnership grants Units in connection with the issuance to such Service Provider of such Units. 

“Blackstone Limited Partners” means the entities listed on the signature pages hereto under the heading
Blackstone Limited Partners and their respective successors and assigns. 
 “Capital Account” means
the separate capital account maintained for each Partner in accordance with Section 5.03 hereof. 

“Capital Contribution” means, with respect to any Partner, the aggregate amount of money contributed to
the Partnership and the Carrying Value of any property (other than money), net of any liabilities assumed by the Partnership upon contribution or to which such property is subject, contributed to the Partnership pursuant to Article V hereof.

 “Carrying Value” means, with respect to any Partnership asset, the asset’s adjusted basis for
U.S. federal income tax purposes, except that the initial carrying value of assets contributed to the Partnership shall be their respective gross fair market values on the date of contribution as determined by the General Partner in its sole
discretion, and the Carrying Values of all Partnership assets shall be adjusted to equal their respective fair market values, in accordance with the rules set forth in Treasury Regulation Section 1.704-1(b)(2)(iv)(f), except as otherwise
provided herein, as of: (a) the date of the acquisition of any additional partnership interest in the Partnership by any new or existing Partner in exchange for more than a de minimis Capital Contribution; (b) the date of the
distribution of more than a de minimis amount of Partnership assets to a Partner; (c) the date a Unit is relinquished to the Partnership; or (d) any other date specified in the Treasury Regulations; provided, however,
that adjustments pursuant to clauses (a), (b) (c) and (d) above shall be made only if such adjustments are deemed necessary or appropriate by the General Partner in its sole discretion to reflect the relative
economic interests of the Partners. The Carrying Value of any Partnership asset distributed to any Partner shall be adjusted immediately before such distribution to equal its fair market value. In the case of any asset that has a Carrying Value that
differs from its adjusted tax basis, Carrying Value shall be adjusted by the amount of depreciation calculated for purposes of the definition of “Profits” and “Losses” rather than the amount of depreciation determined for U.S.
federal income tax purposes, and depreciation shall be calculated by reference to Carrying Value rather than tax basis once Carrying Value differs from tax basis. 

“Cause” with respect to any Limited Partner has the meaning set forth in any effective Award Agreement,
employment agreement or other written contract of engagement entered into between the Partnership and such Limited Partner, or if none, then “Cause” means that the General Partner, based on information then known to the Partnership or the
General Partner, determines in good faith that any of the following have occurred: (A) such Limited Partner’s willful or grossly negligent continued failure to substantially perform such Limited Partner’s material duties to the
Partnership or its Affiliates (other than as a result of total or partial incapacity due to physical or mental illness) for a period of ten (10) days following written notice by the Partnership or the

  
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General Partner to such Limited Partner of such failure, (B) dishonesty in the performance of such Limited Partner’s material duties to the Partnership or any of its Affiliates;
(C) an act or acts on such Limited Partner’s part constituting, or a plea of guilty or nolo contendere to, a crime constituting (x) a felony under the laws of the United States (or any state-law equivalent) or (y) a misdemeanor
involving moral turpitude; (D) such Limited Partner’s willful malfeasance or willful misconduct in connection with such Limited Partner’s duties to the Partnership or its Affiliates or (E) a material breach by such Limited
Partner of any covenant undertaken in Article VIII herein, any effective Award Agreement, employment agreement or any written non-disclosure, non-competition, or non-solicitation covenant or agreement with the Partnership or any of the
Partnership’s subsidiaries, which breach has continued unremedied for more than ten (10) days after the Partnership has provided written notice thereof. 

“CCC Agreement” has the meaning set forth in the recitals of this Agreement. 

“Certificate” has the meaning set forth in the recitals of this Agreement. 

“Class” means the classes of Units into which the limited partner interests in the Partnership may be
classified or divided from time to time by the General Partner in its sole discretion pursuant to the provisions of this Agreement. As of the date of this Agreement the only Class is the Class A Units. Subclasses within a Class shall not be
separate Classes for purposes of this Agreement. For all purposes hereunder and under the Act, only such Classes expressly established under this Agreement, including by the General Partner in accordance with this Agreement, shall be deemed to be a
class of limited partner interests in the Partnership. For the avoidance of doubt, to the extent that the General Partner holds limited partner interests of any Class, the General Partner shall not be deemed to hold a separate Class of such
interests from any other Limited Partner because it is the General Partner. 
 “Class A Units” means
the Units of limited partner interests in the Partnership designated as the “Class A Units” herein and having the rights pertaining thereto as are set forth in this Agreement. 

“Code” means the Internal Revenue Code of 1986, as amended from time to time. 

“Contingencies” has the meaning set forth in Section 9.03(a) hereof. 

“Control” (including the terms “Controlled by” and “under common
Control with”) means the possession, directly or indirectly, of the power to direct or cause the direction of the management and policies of a Person, whether through the ownership of voting securities, as trustee or executor, by
contract or otherwise, including, without limitation, the ownership, directly or indirectly, of securities having the power to elect a majority of the board of directors or similar body governing the affairs of such Person. 

“Disability” with respect to any Limited Partner has the meaning set forth in any effective Award
Agreement, employment agreement or other written contract of engagement entered into between the Partnership and such Limited Partner, or if none, then “Disability” means such Limited Partner’s incapacity due to physical or mental
illness that: 

  
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(a) such Limited Partner is unable to engage in any substantial gainful activity by reason of any medically determinable physical or mental impairment which can be expected to result in death or
can be expected to last for a continuous period of not less than twelve (12) months, or (b) such Limited Partner is, by reason of any medically determinable physical or mental impairment which can be expected to result in death or can be
expected to last for a continuous period of not less than twelve (12) months, receiving income replacement benefits for a period of not less than three (3) months under an accident and health plan covering employees of the Partnership or
an Affiliate. 
 “Disabling Event” means the General Partner ceasing to be the general partner of the
Partnership pursuant to Section 17-402 of the Act. 
 “Dissolution Event” has the meaning set
forth in Section 9.02 hereof. 
 “Encumbrance” means any mortgage, hypothecation, claim,
lien, encumbrance, conditional sales or other title retention agreement, right of first refusal, preemptive right, pledge, option, charge, security interest or other similar interest, easement, judgment or imperfection of title of any nature
whatsoever. 
 “ERISA” means The Employee Retirement Income Security Act of 1974, as amended. 

“Exchange Act” means the U.S. Securities Exchange Act of 1934, as amended, and the rules and
regulations promulgated thereunder. 
 “Exchange Agreement” means the exchange agreement dated as of
or about the date hereof among the Partnership, the General Partner, the Limited Partners of the Partnership from time to time party thereto, and the other parties thereto, as amended from time to time. 

“Exchange Transaction” means an exchange of Units for shares of Class A common stock of the
General Partner pursuant to, and in accordance with, the Exchange Agreement or, at the sole discretion of the General Partner, a Transfer of Units to the General Partner, the Partnership or any of their subsidiaries for other consideration. 

“Fiscal Year” means, unless otherwise determined by the General Partner in its sole discretion in
accordance with Section 11.12 hereof, a fifty-two (52) to fifty-three (53) week period, as applicable, commencing on the first day following the end of the prior Fiscal Year and ending on a Saturday that is closest to
December 31. 
 “GAAP” means accounting principles generally accepted in the United States of
America as in effect from time to time. 
 “General Partner” means, until the consummation of the
IPO, the Pre-existing GP. Simultaneously with the consummation of the IPO and as contemplated by the CCC Agreement, General Partner means Summit Owner Holdco LLC, which will be admitted to the Partnership as the interim general partner of the
Partnership, immediately after which General Partner means IPO Corp, which will be admitted to the Partnership as the general 

  
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partner of the Partnership (and Summit Owner Holdco LLC will no longer be a partner in any capacity), or any successor general partner admitted to the Partnership in accordance with the terms of
this Agreement, in its capacity as general partner of the Partnership. 
 “Highest Partner Tax
Amount” has the meaning set forth in Section 4.01(c) hereof. 
 “Incapacity”
means, with respect to any Person, the bankruptcy, dissolution, termination, entry of an order of incompetence, or the insanity, permanent disability or death of such Person. 

“Indemnitee” (a) the General Partner, (b) any additional or substitute General Partner,
(c) any Person who is or was a Tax Matters Partner, officer or director of the General Partner or any additional or substitute General Partner, (d) any officer or director of the General Partner or any additional or substitute General
Partner who is or was serving at the request of the General Partner or any additional or substitute General Partner as an officer, director, employee, member, partner, Tax Matters Partner, agent, fiduciary or trustee of another Person;
provided that a Person shall not be an Indemnitee by reason of providing, on a fee-for-services basis, trustee, fiduciary or custodial services, (e) any Officer or other Person the General Partner in its sole discretion designates as an
“Indemnitee” for purposes of this Agreement and (f) any heir, executor or administrator with respect to Persons named in clauses (a) through (e). 

“IPO Corp” has the meaning set forth in the preamble of this Agreement. 

“Law” means any statute, law, ordinance, regulation, rule, code, executive order, injunction, judgment,
decree or other order issued or promulgated by any national, supranational, state, federal, provincial, local or municipal government or any administrative or regulatory body with authority therefrom with jurisdiction over the Partnership or any
Partner, as the case may be. 
 “Limited Partner” means each of the Persons from time to time listed
as a limited partner in the books and records of the Partnership, and, for purposes of Section 8.01, Section 8.02, Section 8.03, Section 8.04, Section 8.05 and Section 8.06
hereof, any Personal Planning Vehicle of such Limited Partner, in its capacity as a limited partner of the Partnership. 

“Liquidation Agent” has the meaning set forth in Section 9.03 hereof. 

“Nonrecourse Deductions” has the meaning set forth in Treasury Regulations Section 1.704-2(b)(1).
The amount of Nonrecourse Deductions of the Partnership for a fiscal year equals the net increase, if any, in the amount of Partner Minimum Gain of the Partnership during that fiscal year, determined according to the provisions of Treasury
Regulations Section 1.704-2(c). 
 “Non-U.S. Investments” has the meaning set forth in
Section 6.01(d) hereof. 

  
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 “Officer” means each Person designated as an officer of
the Partnership by the General Partner pursuant to and in accordance with the provisions of Section 3.04 hereof, subject to any resolutions of the General Partner appointing such Person as an officer of the Partnership or relating to
such appointment. 
 “Original Agreement” has the meaning set forth in the recitals of this
Agreement. 
 “Partner Nonrecourse Debt Minimum Gain” means an amount with respect to each partner
nonrecourse debt (as defined in Treasury Regulations Section 1.704-2(b)(4)) equal to the Partner Minimum Gain that would result if such partner nonrecourse debt were treated as a nonrecourse liability (as defined in Treasury Regulations
Section 1.752-1(a)(2)) determined in accordance with Treasury Regulations Section 1.704-2(i)(3). 

“Partner Nonrecourse Deductions” has the meaning set forth in Treasury Regulations
Section 1.704-2(i)(2). 
 “Partners” means, at any time, each person listed as a Partner
(including the General Partner) on the books and records of the Partnership, in each case for so long as he, she or it remains a partner of the Partnership as provided hereunder. 

“Partnership” has the meaning set forth in the preamble of this Agreement. 

“Partner Minimum Gain” has the meaning set forth in Treasury Regulations Sections 1.704-2(b)(2) and
1.704-2(d). 
 “Person” means any individual, estate, corporation, partnership, limited partnership,
limited liability company, limited company, joint venture, trust, unincorporated or governmental organization or any agency or political subdivision thereof. 

“Personal Planning Vehicle” means, in respect of any Person that is a natural person, any other Person
that is not a natural person designated as a “Personal Planning Vehicle” of such natural person in the books and records of the Partnership. 

“Pre-existing GP” has the meaning set forth in the preamble of this Agreement. 

“Primary Indemnification” has the meaning set forth in Section 10.02(a) hereof. 

“Profits” and “Losses” means, for each Fiscal Year or other period, the taxable
income or loss of the Partnership, or particular items thereof, determined in accordance with the accounting method used by the Partnership for U.S. federal income tax purposes with the following adjustments: (a) all items of income, gain, loss
or deduction allocated pursuant to Section 5.05 hereof shall not be taken into account in computing such taxable income or loss; (b) any income of the Partnership that is exempt from U.S. federal income taxation and not otherwise
taken into account in computing Profits and Losses shall be added to such taxable income or loss; (c) if the Carrying Value of any asset differs from its adjusted tax basis for U.S. federal income tax purposes, any gain or loss resulting from a
disposition of such asset shall be calculated with reference to such Carrying Value; (d) upon an adjustment to the Carrying Value (other than an adjustment in respect of depreciation) of 

  
 7 

 
any asset, pursuant to the definition of Carrying Value, the amount of the adjustment shall be included as gain or loss in computing such taxable income or loss; (e) if the Carrying Value of
any asset differs from its adjusted tax basis for U.S. federal income tax purposes, the amount of depreciation, amortization or cost recovery deductions with respect to such asset for purposes of determining Profits and Losses, if any, shall be an
amount which bears the same ratio to such Carrying Value as the U.S. federal income tax depreciation, amortization or other cost recovery deductions bears to such adjusted tax basis (provided that if the U.S. federal income tax depreciation,
amortization or other cost recovery deduction is zero, the General Partner may use any reasonable method for purposes of determining depreciation, amortization or other cost recovery deductions in calculating Profits and Losses); and (f) except
for items in clause (a) above, any expenditures of the Partnership not deductible in computing taxable income or loss, not properly capitalizable and not otherwise taken into account in computing Profits and Losses pursuant to this
definition shall be treated as deductible items. 
 “Service Provider” means any Limited Partner (in
his, her or its individual capacity) or other Person, who at the time in question, is employed by or providing services to the General Partner, the Partnership or any of its subsidiaries. 

“Securities Act” means the U.S. Securities Act of 1933, as amended, and the rules and regulations
promulgated thereunder. 
 “Similar Law” means any law or regulation that could cause the underlying
assets of the Partnership to be treated as assets of the Limited Partner by virtue of its Units and thereby subject the Partnership and the General Partner (or other persons responsible for the investment and operation of the Partnership’s
assets) to laws or regulations that are similar to the fiduciary responsibility or prohibited transaction provisions contained in Title I of ERISA or Section 4975 of the Code. 

“Tax Advances” has the meaning set forth in Section 5.07 hereof. 

“Tax Amount” has the meaning set forth in Section 4.01(c) hereof. 

“Tax Matters Partner” has the meaning set forth in Section 5.08 hereof. 

“Total Percentage Interest” means, with respect to any Partner, the quotient obtained by dividing the
number of Units (vested and unvested) then owned by such Partner by the number of Units (vested and unvested) then owned by all Partners. 

“Transfer” means, in respect of any Unit, property or other asset, any sale, assignment, transfer,
distribution, exchange, mortgage, pledge, hypothecation or other disposition thereof, whether voluntarily or by operation of Law, directly or indirectly, in whole or in part, including, without limitation, the exchange of any Unit for any other
security. 
 “Transferee” means any Person that is a permitted transferee of a Partner’s
interest in the Partnership, or part thereof. 

  
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 “Treasury Regulations” means the income tax regulations,
including temporary and proposed regulations, promulgated under the Code, as such regulations may be amended from time to time (including corresponding provisions of succeeding regulations). 

“Units” means the Class A Units and any other Class of Units that is established in accordance
with this Agreement, which shall constitute limited partner interests in the Partnership as provided in this Agreement and under the Act, entitling the holders thereof to the relative rights, title and interests in the profits, losses, deductions
and credits of the Partnership at any particular time as set forth in this Agreement, and any and all other benefits to which a holder thereof may be entitled as a Partner as provided in this Agreement, together with the obligations of such Partner
to comply with all terms and provisions of this Agreement. 
 “Unvested Units” means Units which are
subject to vesting pursuant to the terms of an Award Agreement or which are listed as unvested Units in the books and records of the Partnership. 

“U.S. Investments” has the meaning set forth in Section 6.01(d) hereof. 

“Vested Percentage Interest” means, with respect to any Partner, the quotient obtained by dividing the
number of Vested Units then owned by such Partner by the number of Vested Units then owned by all Partners. 

“Vested Units” means those Units listed as vested Units in the books and records of the Partnership, as
the same may be amended from time to time in accordance with this Agreement, or which are no longer subject to vesting pursuant to an Award Agreement. 

ARTICLE II 
 FORMATION,
TERM, PURPOSE AND POWERS 
 Section 2.01. Formation. The Partnership has been formed as a limited partnership
pursuant to the provisions of the Act. If requested by the General Partner, the Limited Partners shall promptly execute all certificates and other documents consistent with the terms of this Agreement necessary for the General Partner to accomplish
all filing, recording, publishing and other acts as may be appropriate to comply with all requirements for (a) the formation and operation of a limited partnership under the laws of the State of Delaware, (b) if the General Partner in its
sole discretion deems it advisable, the operation of the Partnership as a limited partnership, or entity in which the Limited Partners have limited liability, in all jurisdictions where the Partnership proposes to operate and (c) all other
filings required to be made by the Partnership. The rights, powers, duties, obligations and liabilities of the Partners shall be determined pursuant to the Act and this Agreement. To the extent that the rights, powers, duties, obligations and
liabilities of any Partner are different by reason of any provision of this Agreement than they would be in the absence of such provision, this Agreement shall, to the extent permitted by the Act, control. The execution, delivery and filing of the
Certificate and each amendment thereto is hereby ratified, approved and confirmed by the Partners. 

  
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 Section 2.02. Name. The name of the Partnership shall be, and the
business of the Partnership shall be conducted under, the name of “Summit Materials Holdings L.P.” and all Partnership business shall be conducted in that name or in such other names that comply with applicable law as the General Partner
in its sole discretion may select from time to time. Subject to the Act, the General Partner in its sole discretion may change the name of the Partnership (and amend this Agreement to reflect such change) at any time and from time to time without
the consent of any other Person. Prompt notification of any such change shall be given to all Partners. 
 Section 2.03.
Term. The term of the Partnership commenced on July 29, 2009, and the term shall continue until the dissolution of the Partnership in accordance with Article IX. The existence of the Partnership shall continue
until cancellation of the Certificate in the manner required by the Act. 
 Section 2.04. Offices. The Partnership
may have offices at such places either within or outside the State of Delaware as the General Partner from time to time may select in its sole discretion. As of the date hereof, the principal place of business and office of the Partnership is
located at 1550 Wynkoop Street, 3rd Floor, Denver, Colorado 80202. 
 Section 2.05. Agent for Service of Process; Existence and Good
Standing; Foreign Qualification. 
 (a) The registered office of the Partnership in the State of Delaware shall be located at c/o
Corporation Service Company, 2711 Centerville Road, Suite 400, Wilmington, New Castle County, Delaware 19808. The name and address of the registered agent of the Partnership for service of process on the Partnership in the State of Delaware shall be
Corporation Service Company, 2711 Centerville Road, Suite 400, Wilmington, New Castle County, Delaware 19808. 
 (b) The General Partner in
its sole discretion may take all action which may be necessary or appropriate (i) for the continuation of the Partnership’s valid existence as a limited partnership under the laws of the State of Delaware (and of each other jurisdiction in
which such existence is necessary to enable the Partnership to conduct the business in which it is engaged) and (ii) for the maintenance, preservation and operation of the business of the Partnership in accordance with the provisions of this
Agreement and applicable laws and regulations. The General Partner in its sole discretion may file or cause to be filed for recordation in the proper office or offices in each other jurisdiction in which the Partnership is formed or qualified, such
certificates (including certificates of formation and fictitious name certificates) and other documents as are required by the applicable statutes, rules or regulations of any such jurisdiction or as are required to reflect the identity of the
Partners. The General Partner may cause the Partnership to comply, to the extent procedures are available and those matters are reasonably within the control of the Officers, with all requirements necessary to qualify the Partnership to do business
in any jurisdiction other than the State of Delaware. 
 Section 2.06. Business Purpose. The Partnership was
formed for the object and purpose of, and the nature and character of the business to be conducted by the Partnership is, engaging in any lawful act or activity for which limited partnerships may be formed under the Act. 

  
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 Section 2.07. Powers of the Partnership. Subject to the limitations set
forth in this Agreement, the Partnership will possess and may exercise all of the powers and privileges granted to it by the Act including, without limitation, the ownership and operation of the assets and other property contributed to the
Partnership by the Partners, by any other Law or this Agreement, together with all powers incidental thereto, so far as such powers are necessary or convenient to the conduct, promotion or attainment of the purpose of the Partnership set forth in
Section 2.06 hereof. Notwithstanding anything herein to the contrary, nothing set forth herein shall be construed as authorizing the Partnership to possess any purpose or power, or to do any act or thing, forbidden by Law to a
partnership organized under the laws of the State of Delaware. 
 Section 2.08. Partners; Admission of New
Partners. Until the consummation of the IPO, the Pre-existing GP shall continue as the General Partner. Simultaneously with the consummation of the IPO and in accordance with the IPO Reorganization Agreement, Summit Owner Holdco
LLC shall be automatically admitted as the General Partner, the Pre-existing GP shall automatically cease to be the General Partner of the Partnership and the Partnership shall be continued without dissolution, and immediately thereafter, IPO Corp
shall be automatically admitted as the General Partner, Summit Owner Holdco LLC shall automatically cease to be the General Partner of the Partnership and the Partnership shall be continued without dissolution. Each of the Persons listed in the
books and records of the Partnership, as the same may be amended from time to time in accordance with this Agreement, by virtue of its execution of this Agreement (including by use of a power of attorney), are admitted as, or continue as, Limited
Partners of the Partnership. The rights, duties and liabilities of the Partners shall be as provided in the Act, except as is otherwise expressly provided herein, and the Partners consent to the variation of such rights, duties and liabilities as
provided herein. Subject to Section 8.09 hereof with respect to substitute Limited Partners, a Person may be admitted from time to time as a new Limited Partner with the written consent of the General Partner in its sole discretion. Each
new Limited Partner shall execute and deliver to the General Partner an appropriate supplement to this Agreement pursuant to which the new Limited Partner agrees to be bound by the terms and conditions of this Agreement, as it may be amended from
time to time. A new General Partner or substitute General Partner may be admitted to the Partnership solely in accordance with Section 8.08 or Section 9.02(e) hereof. 

Section 2.09. Withdrawal. No Partner shall have the right to withdraw as a Partner of the Partnership other than following
the Transfer of all Units owned by such Partner in accordance with Article VIII hereof. 
 Section 2.10. Investment
Representations of Partners. Each Partner hereby represents, warrants and acknowledges to the Partnership that: (a) such Partner has such knowledge and experience in financial and business matters and is capable of evaluating the
merits and risks of an investment in the Partnership and is making an informed investment decision with respect thereto; (b) such Partner is acquiring interests in the Partnership for investment only and not with a view to, or for resale in
connection with, any distribution to the public or public offering thereof; and (c) the execution, delivery and performance of this Agreement have been duly authorized by such Partner. 

  
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 ARTICLE III 

MANAGEMENT 
 Section
3.01. General Partner 
 (a) The business, property and affairs of the Partnership shall be managed under the sole, absolute and
exclusive direction of the General Partner, which may from time to time delegate authority to Officers or to others to act on behalf of the Partnership. 

(b) Without limiting the foregoing provisions of this Section 3.01, the General Partner shall have the general power to manage or
cause the management of the Partnership (which may be delegated to Officers of the Partnership), including, without limitation, the following powers: 

(i) to develop and prepare a business plan each year which will set forth the operating goals and plans for the Partnership; 

(ii) to execute and deliver or to authorize the execution and delivery of contracts, deeds, leases, licenses, instruments of transfer and
other documents on behalf of the Partnership; 
 (iii) to make any expenditures, to lend or borrow money, to assume or guarantee, or
otherwise contract for, indebtedness and other liabilities, to issue evidences of indebtedness and to incur any other obligations; 
 (iv)
to establish and enforce limits of authority and internal controls with respect to all personnel and functions; 
 (v) to engage attorneys,
consultants and accountants for the Partnership; 
 (vi) to develop or cause to be developed accounting procedures for the maintenance of
the Partnership’s books of account; and 
 (vii) to do all such other acts as shall be authorized in this Agreement or by the Partners
in writing from time to time. 
 Section 3.02. Compensation. The General Partner shall not be entitled to any
compensation for services rendered to the Partnership in its capacity as General Partner. 
 Section 3.03. Expenses. The
Partnership shall pay, or cause to be paid, all costs, fees, operating expenses and other expenses of the Partnership (including the costs, fees and expenses of attorneys, accountants or other professionals) incurred in pursuing and conducting, or
otherwise related to, the activities of the Partnership. The Partnership shall also, in the sole discretion of the General Partner, bear and/or reimburse the General Partner for (i) any costs, fees or expenses incurred by the General Partner in
connection with serving as the General Partner and (ii) all other expenses allocable to the Partnership or otherwise incurred by the General Partner in connection with operating the Partnership’s business (including expenses allocated to
the General 

  
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Partner by its Affiliates). To the extent that the General Partner determines in its sole discretion that such expenses are related to the business and affairs of the General Partner that are
conducted through the Partnership and/or its subsidiaries (including expenses that relate to the business and affairs of the Partnership and/or its subsidiaries and that also relate to other activities of the General Partner), the General Partner
may cause the Partnership to pay or bear all expenses of the General Partner, including, without limitation, compensation and meeting costs of any board of directors or similar body of the General Partner, any salary, bonus, incentive compensation
and other amounts paid to any Person including Affiliates of the General Partner to perform services for the Partnership, litigation costs and damages arising from litigation, accounting and legal costs and franchise taxes; provided that the
Partnership shall not pay or bear any income tax obligations of the General Partner. Reimbursements pursuant to this Section 3.03 shall be in addition to any reimbursement to the General Partner as a result of indemnification pursuant to
Section 10.02 hereof. 
 Section 3.04. Officers. Subject to the direction and oversight of the General
Partner, the day-to-day administration of the business of the Partnership may be carried out by persons who may be designated as officers by the General Partner, with titles including but not limited to “assistant secretary,”
“assistant treasurer,” “chairman,” “chief executive officer,” “chief financial officer,” “chief operating officer,” “chief risk officer,” “director,” “general counsel,”
“general manager,” “managing director,” “president,” “principal accounting officer,” “secretary,” “senior chairman,” “senior managing director,” “treasurer,” “vice
chairman” or “vice president,” and as and to the extent authorized by the General Partner in its sole discretion. The officers of the Partnership shall have such titles and powers and perform such duties as shall be determined from
time to time by the General Partner and otherwise as shall customarily pertain to such offices. Any number of offices may be held by the same person. In its sole discretion, the General Partner may choose not to fill any office for any period as it
may deem advisable. All officers and other persons providing services to or for the benefit of the Partnership shall be subject to the supervision and direction of the General Partner and may be removed, with or without cause, from such office by
the General Partner and the authority, duties or responsibilities of any employee, agent or officer of the Partnership may be suspended by the General Partner from time to time, in each case in the sole discretion of the General Partner. The General
Partner shall not cease to be a general partner of the Partnership as a result of the delegation of any duties hereunder. No officer of the Partnership, in its capacity as such, shall be considered a general partner of the Partnership by agreement,
as a result of the performance of its duties hereunder or otherwise. 
 Section 3.05. Authority of Partners. No Partner
(other than the General Partner), in its capacity as such, shall participate in or have any control over the business of the Partnership. Except as expressly provided herein, the Units do not confer any rights upon the Partners to participate in the
affairs of the Partnership described in this Agreement. Except as expressly provided herein, no Partner (other than the General Partner) shall have any right to vote on any matter involving the Partnership, including with respect to any merger,
consolidation, combination or conversion of the Partnership, or any other matter that a Partner might otherwise have the ability to vote on or consent with respect to under the Act, at law, in equity or otherwise. The conduct, control and management
of the Partnership shall be vested exclusively in the General Partner. In all matters relating to or arising out of the conduct of the operation of the Partnership, the decision of the General Partner shall be the decision of the Partnership. Except
as required or permitted by Law, or expressly provided in the ultimate sentence of this Section 3.05 or by separate agreement 

  
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with the Partnership, no Partner who is not also the General Partner (and acting in such capacity) shall take any part in the management or control of the operation or business of the Partnership
in its capacity as a Partner, nor shall any Partner who is not also a General Partner (and acting in such capacity) have any right, authority or power to act for or on behalf of or bind the Partnership in his, her or its capacity as a Partner in any
respect or assume any obligation or responsibility of the Partnership or of any other Partner. Notwithstanding the foregoing, the Partnership may from time to time appoint one or more Partners as officers or employ one or more Partners as employees,
and such Partners, in their capacity as officers or employees of the Partnership (and not, for clarity, in their capacity as Limited Partners of the Partnership), may take part in the control and management of the business of the Partnership to the
extent such authority and power to act for or on behalf of the Partnership has been delegated to them by the General Partner. 
 Section
3.06. Action by Written Consent or Ratification. Any action required or permitted to be taken by the Partners pursuant to this Agreement shall be taken if all Partners whose consent or ratification is required consent thereto or provide a
consent or ratification in writing. 
 ARTICLE IV 

DISTRIBUTIONS 
 Section
4.01. Distributions 
 (a) The General Partner, in its sole discretion, may authorize distributions by the Partnership to the
Partners, which distributions shall be made pro rata in accordance with the Partners’ respective Total Percentage Interests; provided that (i) no amounts otherwise distributable to a Partner on any distribution date in
respect of Unvested Units pursuant to this Section 4.01(a) shall be distributed to any Partner in respect of Unvested Units under this Section 4.01(a), and (ii) such amounts shall instead be distributed to the Partners
pro rata in accordance with the Partners’ respective Vested Percentage Interests. 
 (b) If, from time to time, an Unvested Unit
becomes a Vested Unit, on each subsequent distribution date, the amounts that would otherwise have been distributable to the Partners in accordance with Section 4.01(a) shall instead first be distributed to the Partners holding Vested
Units which were outstanding Unvested Units on the date amounts were previously distributed, until the amount distributed in respect of each such Vested Unit equals the amounts that such Vested Unit would have received had it been a Vested Unit
through all prior distribution dates during which such Vested Unit was an Unvested Unit, pro rata in accordance with all such Partners’ respective Vested Units for which the “catch-up” distributions contemplated by this
Section 4.01(b) are due. Any amounts remaining after all such “catch-up” distributions have been made shall be distributed in accordance with Section 4.01(a). 

(c) The Partnership shall distribute, on a quarterly basis and no later than five (5) days before the date specified in
Section 6655(c)(2) of the Code, to each Partner their pro rata share (based on Total Percentage Interests) of the Tax Amount, from the Available Cash of the Partnership if any, and limited to the amount thereof; provided, a
Partner’s pro rata share of the Tax Amount will only be distributed to such Partner to the extent that the aggregate amount previously distributed to such Partner pursuant to Section 4.01(a) hereof in such Fiscal Year,

  
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Section 4.01(b) hereof on account of distributions made in such Fiscal Year under Section 4.01(a) hereof or this Section 4.01(c) with respect to such Fiscal
Year is less than the amount required to be distributed to such Partner on such date under this Section 4.01(c); provided there will be an adjustment following each Fiscal Year (but no later than one (1) day prior to the due
date for the payment of U.S. federal income taxes by a corporation), and the Partnership will distribute any additional amounts as necessary to make the amounts previously distributed to a Partner pursuant to Section 4.01(a) hereof in
such Fiscal Year, Section 4.01(b) hereof on account of distributions made in such Fiscal Year under Section 4.01(a) hereof or this Section 4.01(c) with respect to such Fiscal Year equal such Partner’s pro
rata share (based on Total Percentage Interests) of the Tax Amount for such Fiscal Year. The “Tax Amount”, calculated for the period beginning on the start of the Fiscal Year through the end of the applicable quarter, is
the Highest Partner Tax Amount divided by the Total Percentage Interest for the Partner described in the immediately following sentence. The “Highest Partner Tax Amount” is, with respect to the Partner receiving the greatest
allocation of estimated net taxable income pursuant to Section 5.06 of this Agreement (relative to its Total Percentage Interest) in the applicable time period, (A) the estimated aggregate taxable income of the Partnership allocated
to such Partner in such time period (for the avoidance of doubt, excluding any adjustments under Sections 743(b) of the Code), multiplied by (B) the Assumed Tax Rate. Distributions pursuant to this provision shall be treated as an advance
against distributions pursuant to Section 4.01(a), Section 4.01(b) and Section 9.03 hereof for all purposes, and, thus, shall reduce/offset subsequent distributions under Section 4.01(a),
Section 4.01(b) and Section 9.03 hereof to the Partners that participate in such distributions pursuant to this Section 4.01(c). 

Section 4.02. Liquidation Distribution. Distributions made upon dissolution of the Partnership shall be made as
provided in Section 9.03 hereof. 
 Section 4.03. Limitations on Distribution. Notwithstanding any
provision to the contrary contained in this Agreement, the General Partner shall not make a distribution to any Partner if such distribution would violate the Act or other applicable Law. 

ARTICLE V 
 CAPITAL
CONTRIBUTIONS; CAPITAL ACCOUNTS; 
 TAX ALLOCATIONS; TAX MATTERS 

Section 5.01. Initial Capital Contributions. The Partners have made, on or prior to the date hereof, Capital
Contributions. 
 Section 5.02. No Additional Capital Contributions. Except as otherwise provided in this Article
V, no Partner shall be required to make additional Capital Contributions to the Partnership without the consent of such Partner or permitted to make additional capital contributions to the Partnership without the consent of the General Partner,
which may be granted or withheld in its sole discretion. 
 Section 5.03. Capital Accounts. A separate capital account (a
“Capital Account”) shall be established and maintained for each Partner in accordance with the provisions of Treasury Regulations Section 1.704-1(b)(2)(iv). The Capital Account of each Partner shall be

  
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credited with such Partner’s Capital Contributions, if any, all Profits allocated to such Partner pursuant to Section 5.04 hereof and any items of income or gain which are
specially allocated pursuant to Section 5.05 hereof; and shall be debited with all Losses allocated to such Partner pursuant to Section 5.04 hereof, any items of loss or deduction of the Partnership specially allocated to
such Partner pursuant to Section 5.05 hereof, and all cash and the Carrying Value of any property (net of liabilities assumed by such Partner and the liabilities to which such property is subject) distributed by the Partnership to such
Partner. Any references in any section of this Agreement to the Capital Account of a Partner shall be deemed to refer to such Capital Account as the same may be credited or debited from time to time as set forth above. In the event of any transfer
of any interest in the Partnership in accordance with the terms of this Agreement, the Transferee shall succeed to the Capital Account of the transferor to the extent it relates to the transferred interest. 

Section 5.04. Allocations of Profits and Losses. Except as otherwise provided in Section 5.05 hereof or this
Agreement, Profits and Losses shall be allocated among the Capital Accounts of the Partners pro rata in accordance with their respective Total Percentage Interests Notwithstanding the foregoing, the General Partner shall make such adjustments
to Capital Accounts as it determines in its sole discretion to be appropriate to ensure allocations are made in accordance with a Partner’s interest in the Partnership. 

Section 5.05. Special Allocations. Notwithstanding any other provision in this Article V: 

(a) Minimum Gain Chargeback. If there is a net decrease in Partnership Minimum Gain or Partner Nonrecourse Debt Minimum
Gain (determined in accordance with the principles of Treasury Regulations Sections 1.704-2(d) and 1.704-2(i)) during any Partnership taxable year, the Partners shall be specially allocated items of Partnership income and gain for such year (and, if
necessary, subsequent years) in an amount equal to their respective shares of such net decrease during such year, determined pursuant to Treasury Regulations Sections 1.704-2(g) and 1.704-2(i)(5). The items to be so allocated shall be determined in
accordance with Treasury Regulations Section 1.704-2(f). This Section 5.05(a) is intended to comply with the minimum gain chargeback requirements in such Treasury Regulations Sections and shall be interpreted consistently therewith;
including that no chargeback shall be required to the extent of the exceptions provided in Treasury Regulations Sections 1.704-2(f) and 1.704-2(i)(4). 

(b) Qualified Income Offset. If any Partner unexpectedly receives any adjustments, allocations, or distributions described
in Treasury Regulations Section 1.704-1(b)(2)(ii)(d)(4), (5) or (6), items of Partnership income and gain shall be specially allocated to such Partner in an amount and manner sufficient to eliminate the deficit balance in such
Partner’s Adjusted Capital Account Balance created by such adjustments, allocations or distributions as promptly as possible; provided that an allocation pursuant to this Section 5.05(b) shall be made only to the extent that
a Partner would have a deficit Adjusted Capital Account Balance in excess of such sum after all other allocations provided for in this Article V have been tentatively made as if this Section 5.05(b) were not in this Agreement.
This Section 5.05(b) is intended to comply with the “qualified income offset” requirement of the Code and shall be interpreted consistently therewith. 

  
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 (c) Gross Income Allocation. If any Partner has a deficit Capital Account at
the end of any Fiscal Year which is in excess of the sum of (i) the amount such Partner is obligated to restore, if any, pursuant to any provision of this Agreement, and (ii) the amount such Partner is deemed to be obligated to restore
pursuant to the penultimate sentences of Treasury Regulations Section 1.704-2(g)(1) and 1.704-2(i)(5), each such Partner shall be specially allocated items of Partnership income and gain in the amount of such excess as quickly as possible;
provided that an allocation pursuant to this Section 5.05(c) shall be made only if and to the extent that a Partner would have a deficit Capital Account in excess of such sum after all other allocations provided for in this
Article V have been tentatively made as if Section 5.05(b) hereof and this Section 5.05(c) were not in this Agreement. 

(d) Nonrecourse Deductions. Nonrecourse Deductions shall be allocated to the Partners in accordance with their respective
Total Percentage Interests. 
 (e) Partner Nonrecourse Deductions. Partner Nonrecourse Deductions for any taxable period
shall be allocated to the Partner who bears the economic risk of loss with respect to the liability to which such Partner Nonrecourse Deductions are attributable in accordance with Treasury Regulations Section 1.704-2(j). 

(f) Ameliorative Allocations. Any special allocations of income or gain pursuant to Section 5.05(b) or
Section 5.05(c) hereof shall be taken into account in computing subsequent allocations pursuant to Section 5.04 hereof and this Section 5.05(f), so that the net amount of any items so allocated and all other items
allocated to each Partner shall, to the extent possible, be equal to the net amount that would have been allocated to each Partner if such allocations pursuant to Section 5.05(b) or Section 5.05(c) hereof had not occurred.

 Section 5.06. Tax Allocations. For income tax purposes, each item of income, gain, loss and deduction of the
Partnership shall be allocated among the Partners in the same manner as the corresponding items of Profits and Losses and specially allocated items are allocated for Capital Account purposes; provided that in the case of any asset the
Carrying Value of which differs from its adjusted tax basis for U.S. federal income tax purposes, income, gain, loss and deduction with respect to such asset shall be allocated solely for income tax purposes in accordance with the principles of
Sections 704(b) and (c) of the Code (in any manner determined by the General Partner and permitted by the Code and Treasury Regulations) so as to take account of the difference between Carrying Value and adjusted basis of such asset;
provided, further, that the Partnership shall use the traditional method (as provided in Treasury Regulations Section 1.704-3(b)) for all Section 704(c) allocations). Notwithstanding the foregoing (other than the immediately
preceding proviso), the General Partner shall make such allocations for tax purposes as it determines in its sole discretion to be appropriate to ensure allocations are made in accordance with a Partner’s interest in the Partnership. 

Section 5.07. Tax Advances. To the extent the General Partner reasonably believes that the Partnership is required by law
to withhold or to make tax payments on behalf of or with respect to any Partner or the Partnership is subjected to tax itself by reason of the status of any Partner (“Tax Advances”), the General Partner may cause the
Partnership to withhold such amounts and cause the Partnership to make such tax payments as so required. All Tax Advances made on behalf of a Partner shall be repaid by reducing the amount of the current or next

  
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succeeding distribution or distributions which would otherwise have been made to such Partner or, if such distributions are not sufficient for that purpose, by so reducing the proceeds of
liquidation otherwise payable to such Partner. For all purposes of this Agreement such Partner shall be treated as having received the amount of the distribution that is equal to the Tax Advance. Each Partner hereby agrees to indemnify and hold
harmless the Partnership and the other Partners from and against any liability (including, without limitation, any liability for taxes, penalties, additions to tax or interest other than any penalties, additions to tax or interest imposed as a
result of the Partnership’s failure to withhold or make a tax payment on behalf of such Partner which withholding or payment is required pursuant to applicable Law but only to the extent amounts sufficient to pay such taxes were not timely
distributed to the Partner pursuant to Section 4.01(c) hereof) with respect to income attributable to or distributions or other payments to such Partner. 

Section 5.08. Tax Matters. The General Partner shall be the initial “tax matters partner” within the meaning of
Section 6231(a)(7) of the Code (the “Tax Matters Partner”). The Partnership shall file as a partnership for federal, state, provincial and local income tax purposes, except where otherwise required by Law. All elections
required or permitted to be made by the Partnership, and all other tax decisions and determinations relating to federal, state, provincial or local tax matters of the Partnership, shall be made by the Tax Matters Partner, in consultation with the
Partnership’s attorneys and/or accountants. Tax audits, controversies and litigations shall be conducted under the direction of the Tax Matters Partner. As soon as reasonably practicable after the end of each taxable year (but not later than
sixty (60) days following the end of each taxable year), the Partnership shall send to each Partner a copy of U.S. Internal Revenue Service Schedule K-1 (which Schedule K-1 shall separately state, to the extent reasonably required by any
Partner, any items of all items of income, gain, loss or deduction with respect to U.S. Investments and Non-U.S. Investments, in accordance with the tracking contemplated by Section 6.01(d) hereof), and any comparable statements required
by applicable U.S. state or local income tax Law as a result of the Partnership’s activities or investments, with respect to such Fiscal Year. The Partnership also shall provide the Partners with such other information as may be reasonably
requested for purposes of allowing the Partners to prepare and file their own tax returns; provided that any costs or expenses with respect to the foregoing shall be borne by the requesting Partner. 

Section 5.09. Other Allocation Provisions. Certain of the foregoing provisions and the other provisions of this Agreement
relating to the maintenance of Capital Accounts are intended to comply with Treasury Regulations Section 1.704-1(b) and shall be interpreted and applied in a manner consistent with such regulations. In
addition to amendments effected in accordance with Section 11.12 or otherwise in accordance with this Agreement, Section 5.03, Section 5.04 and Section 5.05 hereof may also, so long as any such
amendment does not materially change the relative economic interests of the Partners, be amended at any time by the General Partner if necessary, in the opinion of tax counsel to the Partnership, to comply with such regulations or any applicable
Law. 
 ARTICLE VI 

BOOKS AND RECORDS; REPORTS 

Section 6.01. Books and Records 

  
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 (a) At all times during the continuance of the Partnership, the General Partner shall prepare and
maintain separate books of account for the Partnership in accordance with GAAP. 
 (b) Except as limited by Section 6.01(c)
hereof, each Limited Partner shall have the right to receive, for a purpose reasonably related to such Limited Partner’s interest as a Limited Partner of the Partnership, upon reasonable written demand stating the purpose of such demand and at
such Limited Partner’s own expense: 
 (i) a copy of the Certificate and this Agreement and all amendments thereto, together with a
copy of the executed copies of all powers of attorney pursuant to which the Certificate and this Agreement and all amendments thereto have been executed; and 

(ii) promptly after their becoming available, copies of the Partnership’s U.S. federal income tax returns for the three most recent
years. 
 (c) The General Partner may keep confidential from the Limited Partners, for such period of time as the General Partner determines
in its sole discretion, (i) any information that the General Partner reasonably believes to be in the nature of trade secrets or (ii) other information the disclosure of which the General Partner believes is not in the best interests of
the Partnership, could damage the Partnership or its business or that the Partnership is required by law or by agreement with any third party to keep confidential. 

(d) The Partners acknowledge and agree that the Partnership shall separately track the performance of the operations, assets, acquisitions and
investments of the Partnership and its Subsidiaries located in the U.S. (and any indebtedness or liabilities with respect thereto) (“U.S. Investments”) and the operations, assets, acquisitions and investments of the
Partnership and its Subsidiaries located outside of the U.S. (and any indebtedness or liabilities with respect thereto) (“Non-U.S. Investments”). For the avoidance of doubt, such separate tracking shall reflect the sources
and uses of funds with respect to U.S. Investments and Non-U.S. Investments. Separate and distinct records shall be maintained with respect to U.S. Investments generally and Non-U.S. Investments generally, and the assets and liabilities associated
with U.S. Investments and Non-U.S. Investments shall be held and accounted for separately. In the event of a distribution made by the Partnership, (A) where distributed assets are derived from income or other proceeds separately arising out of
U.S. Investments, such distributed assets shall be separately accounted for from any distributions in respect of Non-U.S. Investments, and (B) where the distributed assets are derived from income or other proceeds arising out of Non-U.S.
Investments, such distributed assets shall be separately accounted for from any distributions in respect of U.S. Investments. 
 ARTICLE
VII 
 PARTNERSHIP UNITS 

Section 7.01. Units. Limited partner interests in the Partnership shall be represented by Units. At the effectiveness of
this Agreement, the Units are composed of one Class: “Class A Units.” The General Partner in its sole discretion may establish and issue, from time to time in accordance with such procedures as the General Partner shall determine from
time to time, additional Units, in one or more Classes or series of Units, or other Partnership securities, at such 

  
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price, and with such designations, preferences and relative, participating, optional or other special rights, powers and duties (which may be senior to existing Units, Classes and series of Units
or other Partnership securities), as shall be determined by the General Partner without the approval of any Partner or any other Person who may acquire an interest in any of the Units, including (i) the right of such Units to share in Profits
and Losses or items thereof; (ii) the right of such Units to share in Partnership distributions; (iii) the rights of such Units upon dissolution and liquidation of the Partnership; (iv) whether, and the terms and conditions upon
which, the Partnership may or shall be required to redeem such Units (including sinking fund provisions); (v) whether such Units are issued with the privilege of conversion or exchange and, if so, the terms and conditions of such conversion or
exchange; (vi) the terms and conditions upon which such Units will be issued, evidenced by certificates and assigned or transferred; (vii) the method for determining the Total Percentage Interest as to such Units; (viii) the terms and
conditions of the issuance of such Units (including, without limitation, the amount and form of consideration, if any, to be received by the Partnership in respect thereof, the General Partner being expressly authorized, in its sole discretion, to
cause the Partnership to issue such Units for less than fair market value); and (ix) the right, if any, of the holder of such Units to vote on Partnership matters, including matters relating to the relative designations, preferences, rights,
powers and duties of such Units. The General Partner in its sole discretion, without the approval of any Partner or any other Person, is authorized (i) to issue Units or other Partnership securities of any newly established Class or any
existing Class to Partners or other Persons who may acquire an interest in the Partnership; and (ii) to amend this Agreement to reflect the creation of any such new Class, the issuance of Units or other Partnership securities of such Class, and
the admission of any Person as a Partner which has received Units or other Partnership securities. Except as expressly provided in this Agreement to the contrary, any reference to “Units” shall include the Class A Units and Units of
any other Class or series that may be established in accordance with this Agreement. All Units of a particular Class shall have identical rights in all respects as all other Units of such Class, except in each case as otherwise specified in this
Agreement. 
 Section 7.02. Reclassification of Interests. In accordance with the IPO Reorganization Agreement, all
Interests (as defined in the Original Agreement) in the Partnership issued and outstanding immediately prior to the effectiveness of this Agreement are hereby converted into Class A Units and each Limited Partner owns the number of Class A
Units set forth opposite the name of such Limited Partner in the register of the Partnership. 
 Section 7.03. Register; Certificates;
Legends. The register of the Partnership shall be the definitive record of ownership of each Unit and all relevant information with respect to each Partner. Unless the General Partner in its sole discretion shall determine otherwise,
Units shall be uncertificated and recorded in the books and records of the Partnership. Certificates, if any, representing Units that are issued to any Partner shall bear a legend in substantially the following form: 

THE SECURITIES REPRESENTED BY THIS CERTIFICATE HAVE NOT BEEN REGISTERED UNDER THE SECURITIES ACT OF 1933, AS AMENDED, OR ANY OTHER STATE OR
FOREIGN SECURITIES LAWS AND MAY NOT BE OFFERED, SOLD, OR TRANSFERRED EXCEPT IN COMPLIANCE THEREWITH. THE SECURITIES REPRESENTED BY THIS CERTIFICATE ARE ALSO SUBJECT TO ADDITIONAL RESTRICTIONS ON TRANSFER AS SET FORTH IN THE FOURTH

  
 20 

 
AMENDED AND RESTATED LIMITED PARTNERSHIP AGREEMENT DATED AS OF [            ], 2015, AS AMENDED FROM TIME TO TIME A COPY OF WHICH WILL
BE FURNISHED BY SUMMIT MATERIALS HOLDINGS L.P. UPON REQUEST. 
 Section 7.04. Registered Partners. The Partnership shall
be entitled to recognize the exclusive right of a Person registered on its records as the owner of Units for all purposes and shall not be bound to recognize any equitable or other claim to or interest in Units on the part of any other Person,
whether or not it shall have express or other notice thereof, except as otherwise provided by the Act or other applicable Law. 
 ARTICLE
VIII 
 VESTING; FORFEITURE OF INTERESTS; TRANSFER RESTRICTIONS 

Section 8.01. Vesting of Unvested Units. 

(a) Unvested Units shall become vested pursuant to the terms of an Award Agreement entered into by and between the General Partner and the
applicable Partner, and shall thereafter be Vested Units for all purposes of this Agreement. 
 (b) The General Partner in its sole
discretion may authorize the earlier vesting of all or a portion of Unvested Units owned by any one or more Limited Partners at any time and from time to time, and in such event, such Unvested Units shall vest and thereafter be Vested Units for all
purposes of this Agreement. Any such determination in the General Partner’s discretion in respect of Unvested Units shall be final and binding. Such determinations need not be uniform and may be made selectively among Limited Partners, whether
or not such Limited Partners are similarly situated, and shall not constitute the breach of any duty hereunder or otherwise existing at law, in equity or otherwise. 

(c) Upon the vesting of any Unvested Units in accordance with this Section 8.01 or an Award Agreement entered into in accordance
with this Agreement, the General Partner shall modify the books and records of the Partnership to reflect such vesting. 
 Section 8.02.
Forfeiture of Units 
 (a) Except as otherwise agreed to in writing between the General Partner and the applicable Person and
reflected in the books and records of the Partnership, if a Person that is a Service Provider ceases to be a Service Provider for any reason, all Unvested Units held by such Person (or any Personal Planning Vehicle of such Person), and/or in which
such Person (or any Personal Planning Vehicle of such Person) has an indirect interest, as set forth in the books and records of the Partnership, shall be immediately forfeited without any consideration, and any such Person (or any such Personal
Planning Vehicle) shall cease to own or have any rights, directly or indirectly, with respect to such forfeited Unvested Units. 
 (b)
Except as otherwise agreed to in writing between the General Partner and the applicable Person and reflected in the books and records of the Partnership, if the General Partner determines in good faith that Cause exists with respect to any Person
that is or was at any time a Service Provider, the Units (whether or not vested) held by such Person (or any Personal Planning 

  
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Vehicle of such Person), and/or in which such Person (or any Personal Planning Vehicle of such Person) has an indirect interest, as set forth in the books and records of the Partnership, shall be
immediately forfeited without any consideration, and any such Person (or any such Personal Planning Vehicle) shall cease to own or have any rights, directly or indirectly, with respect to such forfeited Units. Such determinations need not be uniform
and may be made selectively among such Persons, whether or not such Persons are similarly situated, and shall not constitute the breach by the General Partner or any of its directors, managers, officers or members of any duty (including any
fiduciary duty) hereunder or otherwise existing at law, in equity or otherwise. 
 (c) Upon the forfeiture of any Units in accordance with
this Section 8.02, such Units shall be cancelled and the General Partner shall modify the books and records of the Partnership to reflect such forfeiture and cancellation. 

Section 8.03. Limited Partner Transfers 

(a) Except as otherwise agreed to in writing between the General Partner and the applicable Limited Partner and reflected in the books and
records of the Partnership, no Limited Partner or Assignee thereof may Transfer (including pursuant to an Exchange Transaction) all or any portion of its Units or other interest in the Partnership (or beneficial interest therein) without the prior
consent of the General Partner, which consent may be given or withheld, or made subject to such conditions (including, without limitation, the receipt of such legal opinions and other documents that the General Partner may require) as are determined
by the General Partner, in each case in the General Partner’s sole discretion, and which consent may be in the form of a plan or program entered into or approved by the General Partner, in its sole discretion. Any such determination in the
General Partner’s discretion in respect of Units shall be final and binding. Such determinations need not be uniform and may be made selectively among Limited Partners, whether or not such Limited Partners are similarly situated, and shall not
constitute the breach of any duty hereunder or otherwise existing at law, in equity or otherwise. Any purported Transfer of Units that is not in accordance with, or subsequently violates, this Agreement shall be, to the fullest extent permitted by
law, null and void. 
 (b) Notwithstanding anything otherwise to the contrary in this Section 8.03, each Limited Partner may
Transfer Units in Exchange Transactions pursuant to, and in accordance with, the Exchange Agreement; provided that such Exchange Transactions shall be effected in compliance with policies that the General Partner may adopt or promulgate from
time to time (including policies requiring the use of designated administrators or brokers) in its sole discretion. Notwithstanding Section 17-702(d) of the Act, any Class A Units acquired by the Partnership pursuant to an Exchange
Transaction shall not be cancelled and shall be deemed re-issued to the General Partner by the Partnership. 
 (c) Notwithstanding anything
otherwise to the contrary in this Section 8.03, a Personal Planning Vehicle of a Limited Partner may Transfer Units: (i) to the donor thereof; (ii) if the Personal Planning Vehicle is a grantor retained annuity trust and the
trustee(s) of such grantor retained annuity trust is obligated to make one or more distributions to the donor of the grantor retained annuity trust, the estate of the donor of the grantor retained annuity trust, the spouse of the donor of the
grantor retained annuity trust or the estate of the spouse of the donor of the grantor retained annuity trust, to any such Persons; or (iii) upon the death of such Limited Partner, to the spouse of such Limited Partner or a trust for which a
deduction under Section 2056 or 2056A (or any successor provisions) of the Code may be sought. 

  
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 (d) Notwithstanding anything otherwise to the contrary in this Section 8.03, but
subject to Section 8.06(b), Blackstone Limited Partners may Transfer all or any portion of their Units or other interest in the Partnership (or beneficial interest therein) without the prior consent of the General Partner. 

Section 8.04. Mandatory Exchanges. The General Partner may in its sole discretion at any time and from time to time,
without the consent of any Limited Partner or other Person, cause to be Transferred in an Exchange Transaction any and all Units, except for Units held by any Person that is a Blackstone Limited Partner or who is Service Provider at the time in
question and/or in which a Person that is a Blackstone Limited Partner or a Service Provider at the time in question has an indirect interest as set forth in the books and records of the Partnership. Any such determinations by the General Partner
need not be uniform and may be made selectively among Limited Partners, whether or not such Limited Partners are similarly situated. In addition, the General Partner may, with the consent of Partners whose Vested Percentage Interests exceed 66 2/3%
of the Vested Percentage Interests of all Partners in the aggregate, require all Limited Partners to Transfer in an Exchange Transaction all Units held by them; provided that the prior written consent of each Blackstone Limited Partner
affected by any such proposed Transfer will be required. 
 Section 8.05. Encumbrances. No Limited Partner or Assignee
may create an Encumbrance with respect to all or any portion of its Units (or any beneficial interest therein) other than Encumbrances that run in favor of the Limited Partner unless the General Partner consents in writing thereto, which consent may
be given or withheld, or made subject to such conditions as are determined by the General Partner, in the General Partner’s sole discretion. Consent of the General Partner shall be withheld until the holder of the Encumbrance acknowledges the
terms and conditions of this Agreement. Any purported Encumbrance that is not in accordance with this Agreement shall be, to the fullest extent permitted by law, null and void. 

Section 8.06. Further Restrictions. 

(a) Notwithstanding any contrary provision in this Agreement, the General Partner may impose such vesting requirements, forfeiture provisions,
Transfer restrictions, minimum retained ownership requirements or other similar provisions with respect to any Units that are outstanding as of the date of this Agreement or are created thereafter, with the written consent of the holder of such
Units. Such requirements, provisions and restrictions need not be uniform and may be waived or released by the General Partner in its sole discretion with respect to all or a portion of the Units owned by any one or more Limited Partners at any time
and from time to time, and shall not constitute the breach of any duty hereunder or otherwise existing at law, in equity or otherwise. 

(b) Notwithstanding any contrary provision in this Agreement, in no event may any Transfer of a Unit be made by any Limited Partner or
Assignee if: 

  
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 (i) such Transfer is made to any Person who lacks the legal right, power or capacity to own such
Unit; 
 (ii) such Transfer would require the registration of such transferred Unit or of any Class of Unit pursuant to any applicable U.S.
federal or state securities laws (including, without limitation, the Securities Act or the Exchange Act) or other non-U.S. securities laws (including Canadian provincial or territorial securities laws) or would constitute a non-exempt distribution
pursuant to applicable provincial or state securities laws; 
 (iii) such Transfer would cause (i) all or any portion of the assets of
the Partnership to (A) constitute “plan assets” (under ERISA, the Code or any applicable Similar Law) of any existing or contemplated Limited Partner, or (B) be subject to the provisions of ERISA, Section 4975 of the Code or
any applicable Similar Law, or (ii) the General Partner to become a fiduciary with respect to any existing or contemplated Limited Partner, pursuant to ERISA, any applicable Similar Law, or otherwise; 

(iv) to the extent requested by the General Partner, the Partnership does not receive such legal and/or tax opinions and written instruments
(including, without limitation, copies of any instruments of Transfer and such Assignee’s consent to be bound by this Agreement as an Assignee) that are in a form satisfactory to the General Partner, as determined in the General Partner’s
sole discretion; provided that no legal and/or tax opinions will be required for any Transfer of a Unit by a Blackstone Limited Partner; or 

(v) the General Partner shall determine in its sole discretion that such Transfer would pose a material risk that the Partnership would be
treated as a “publicly traded partnership” within the meaning of Section 7704 of the Code and the regulations promulgated thereunder. 

(c) In addition, notwithstanding any contrary provision in this Agreement, to the extent the General Partner shall determine that interests in
the Partnership do not meet the requirements of Treasury Regulation Section 1.7704-1(h), the General Partner may impose such restrictions on the Transfer of Units or other interests in the Partnership as the General Partner may determine in its
sole discretion to be necessary or advisable so that the Partnership is not treated as a “publicly traded partnership” within the meaning of Section 7704 of the Code and the regulations promulgated thereunder. 

(d) To the fullest extent permitted by law, any Transfer in violation of this Article VIII shall be deemed null and void ab initio
and of no effect. 
 Section 8.07. Rights of Assignees. Subject to Section 8.06(b) hereof, the Transferee
of any permitted Transfer pursuant to this Article VIII will be an assignee only (“Assignee”), and only will receive, to the extent transferred, the distributions and allocations of income, gain, loss, deduction,
credit or similar item to which the Partner which transferred its Units would be entitled, and such Assignee will not be entitled or enabled to exercise any other rights or powers of a Partner, such other rights, and all obligations relating to, or
in connection with, such interest remaining with the transferring Partner. The transferring Partner will remain a Partner even if it has transferred all of its Units to one or more Assignees until such time as the Assignee(s) is admitted to the
Partnership as a Partner pursuant to Section 8.09 hereof. 

  
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 Section 8.08. Admissions, Withdrawals and Removals 

(a) No Person may be admitted to the Partnership as an additional General Partner or substitute General Partner without the prior written
consent of each incumbent General Partner, which consent may be given or withheld, or made subject to such conditions as are determined by each incumbent General Partner, in each case in the sole discretion of each incumbent General Partner. A
General Partner will not be entitled to Transfer all of its Units or to withdraw from being a General Partner of the Partnership unless another General Partner shall have been admitted hereunder (and not have previously been removed or withdrawn).

 (b) No Limited Partner will be removed or entitled to withdraw from being a Partner of the Partnership except in accordance with
Section 8.10 hereof. Any additional General Partner or substitute General Partner admitted as a General Partner of the Partnership pursuant to this Section 8.08 is hereby authorized to, and shall, continue the Partnership
without dissolution. 
 (c) Except as otherwise provided in Article IX hereof or the Act, no admission, substitution, withdrawal or
removal of a Partner will cause the dissolution of the Partnership. To the fullest extent permitted by law, any purported admission, withdrawal or removal that is not in accordance with this Agreement shall be null and void. 

Section 8.09. Admission of Assignees as Substitute Limited Partners. An Assignee will become a substitute Limited Partner
only if and when each of the following conditions is satisfied: 
 (a) the General Partner consents in writing to such admission, which
consent may be given or withheld, or made subject to such conditions as are determined by the General Partner, in each case in the General Partner’s sole discretion; 

(b) if required by the General Partner, the General Partner receives written instruments (including, without limitation, copies of any
instruments of Transfer and such Assignee’s consent to be bound by this Agreement as a substitute Limited Partner) that are in a form satisfactory to the General Partner (as determined in its sole discretion); 

(c) if required by the General Partner with respect to any Limited Partner other than a Blackstone Limited Partner, the General Partner
receives an opinion of counsel satisfactory to the General Partner to the effect that such Transfer is in compliance with this Agreement and all applicable Law; and 

(d) if required by the General Partner, the parties to the Transfer, or any one of them, pays all of the Partnership’s reasonable
expenses connected with such Transfer (including, but not limited to, the reasonable legal and accounting fees of the Partnership). 

Section 8.10. Withdrawal and Removal of Limited Partners. Subject to Section 8.07 hereof, if a Limited Partner
ceases to hold any Units, including as a result of a forfeiture of Units pursuant to Section 8.02 hereof, then such Limited Partner shall cease to be a Limited Partner and to have the power to exercise any rights or powers of a Limited
Partner. 

  
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 ARTICLE IX 

DISSOLUTION, LIQUIDATION AND TERMINATION 

Section 9.01. No Dissolution. Except as required by the Act, the Partnership shall not be dissolved by the admission of
additional Partners or the withdrawal of Partners in accordance with the terms of this Agreement. The Partnership may be dissolved, liquidated, wound up and terminated only pursuant to the provisions of this Article IX, and the Partners
hereby irrevocably waive any and all other rights they may have to cause a dissolution of the Partnership or a sale or partition of any or all of the Partnership assets. 

Section 9.02. Events Causing Dissolution. The Partnership shall be dissolved and its affairs shall be wound up upon the
occurrence of any of the following events (each, a “Dissolution Event”): 
 (a) the entry of a decree of judicial
dissolution of the Partnership under Section 17-802 of the Act upon the finding by a court of competent jurisdiction that it is not reasonably practicable to carry on the business of the Partnership in conformity with this Agreement; 

(b) any event which makes it unlawful for the business of the Partnership to be carried on by the Partners; 

(c) the written consent of all Partners; 

(d) at any time there are no Limited Partners, unless the Partnership is continued in accordance with the Act; 

(e) the Incapacity or removal of the General Partner or the occurrence of a Disabling Event with respect to the General Partner;
provided that the Partnership will not be dissolved or required to be wound up in connection with any of the events specified in this Section 9.02(e) if: (i) at the time of the occurrence of such event there is at least one
other general partner of the Partnership who is hereby authorized to, and elects to, carry on the business of the Partnership; or (ii) all remaining Limited Partners consent to or ratify the continuation of the business of the Partnership and
the appointment of another general partner of the Partnership, effective as of the event that caused the General Partner to cease to be a general partner of the Partnership, within one hundred twenty (120) days following the occurrence of any
such event, which consent shall be deemed (and if requested each Limited Partner shall provide a written consent or ratification) to have been given for all Limited Partners if the holders of more than 50% of the Vested Units then outstanding agree
in writing to so continue the business of the Partnership; or 
 (f) the determination of the General Partner in its sole discretion;
provided that in the event of a dissolution pursuant to this Section 9.02(f), the relative economic rights of each Class of Units immediately prior to such dissolution shall be preserved to the greatest extent practicable with
respect to distributions made to Partners pursuant to Section 9.03 hereof in connection with the winding up of the Partnership, taking into consideration tax and other legal 

  
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constraints that may adversely affect one or more parties hereto and subject to compliance with applicable laws and regulations, unless, and to the extent that, with respect to any Class of
Units, holders of not less than 90% of the Units of such Class consent in writing to a treatment other than as described above. 

Section 9.03. Distribution upon Dissolution. Upon dissolution, the Partnership shall not be terminated and shall continue
until the winding up of the affairs of the Partnership is completed. Upon the winding up of the Partnership, the General Partner, or any other Person designated by the General Partner (the “Liquidation Agent”), shall take
full account of the assets and liabilities of the Partnership and shall, unless the General Partner determines otherwise, liquidate the assets of the Partnership as promptly as is consistent with obtaining the fair value thereof. The proceeds of any
liquidation shall be applied and distributed in the following order: 
 (a) First, to the satisfaction of debts and liabilities of the
Partnership (including satisfaction of all indebtedness to Partners and/or their Affiliates to the extent otherwise permitted by law) including the expenses of liquidation, and including the establishment of any reserve which the Liquidation Agent
shall deem reasonably necessary for any contingent, conditional or unmatured contractual liabilities or obligations of the Partnership (“Contingencies”). Any such reserve may be paid over by the Liquidation Agent to any
attorney-at-law, or acceptable party, as escrow agent, to be held for disbursement in payment of any Contingencies and, at the expiration of such period as shall be deemed advisable by the Liquidation Agent for distribution of the balance in the
manner hereinafter provided in this Section 9.03; 
 (b) Second, to the satisfaction of “catch-up” distributions due
pursuant to Section 4.02(b), if any, to the Partners holding any such Vested Units for which such distributions are due pro rata in accordance with all such Partners’ respective Vested Units for which such distributions are
due; and 
 (c) The balance, if any, to the Partners, pro rata in accordance with the Partners’ respective Vested Percentage
Interests (taking into account any amounts previously deemed distributed pursuant to Section 5.07 and not offset against prior distributions). 

Section 9.04. Time for Liquidation. A reasonable amount of time shall be allowed for the orderly liquidation of the assets
of the Partnership and the discharge of liabilities to creditors so as to enable the Liquidation Agent to minimize the losses attendant upon such liquidation. 

Section 9.05. Termination. The Partnership shall terminate when all of the assets of the Partnership, after payment of or
due provision for all debts, liabilities and obligations of the Partnership, shall have been distributed to the holders of Units in the manner provided for in this Article IX, and the Certificate shall have been cancelled in the manner
required by the Act. 
 Section 9.06. Claims of the Partners. The Partners shall look solely to the Partnership’s
assets for the return of their Capital Contributions, and if the assets of the Partnership remaining after payment of or due provision for all debts, liabilities and obligations of the Partnership are insufficient to return such Capital
Contributions, the Partners shall have no recourse against the Partnership or any other Partner or any other Person. No Partner with a negative balance 

  
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in such Partner’s Capital Account shall have any obligation to the Partnership or to the other Partners or to any creditor or other Person to restore such negative balance during the
existence of the Partnership, upon dissolution or termination of the Partnership or otherwise, except to the extent required by the Act. 

Section 9.07. Survival of Certain Provisions. Notwithstanding anything to the contrary in this Agreement, the provisions of
Section 5.07, Section 10.02, Section 11.09 and Section 11.10 hereof shall survive the termination of the Partnership. 

ARTICLE X 
 LIABILITY
AND INDEMNIFICATION 
 Section 10.01. Liability of Partners 

(a) No Limited Partner and no Affiliate, manager, member, employee or agent of a Limited Partner shall be liable for any debt, obligation or
liability of the Partnership or of any other Partner or have any obligation to restore any deficit balance in its Capital Account solely by reason of being a Limited Partner of the Partnership, except to the extent required by the Act. 

(b) This Agreement is not intended to, and does not, create or impose any duty (including any fiduciary duty) other than express contractual
duties set forth herein on any of the Partners (including without limitation, the General Partner) hereto or on their respective Affiliates. Further, notwithstanding any other provision of this Agreement or any duty otherwise existing at law or in
equity, the parties hereto agree that no Limited Partner or General Partner shall, to the fullest extent permitted by law, have duties (including fiduciary duties) other than express contractual duties set forth herein to any other Partner or to the
Partnership, and in doing so, recognize, acknowledge and agree that their duties and obligations to one another and to the Partnership are only as expressly set forth in this Agreement; provided, however, that each Partner shall have
the duty to act in accordance with the implied contractual covenant of good faith and fair dealing. 
 (c) To the extent that, at law or in
equity, any Partner (including without limitation, the General Partner) has duties (including fiduciary duties) and liabilities relating thereto to the Partnership, to another Partner or to another Person who is a party to or is otherwise bound by
this Agreement, the Partners (including without limitation, the General Partner) acting under this Agreement will not be liable to the Partnership, to any such other Partner or to any such other Person who is a party to or is otherwise bound by this
Agreement, for their good faith reliance on the provisions of this Agreement. The provisions of this Agreement, to the extent that they restrict or eliminate the duties and liabilities relating thereto of any Partner (including without limitation,
the General Partner) otherwise existing at law or in equity, are agreed by the Partners to replace to that extent such other duties and liabilities of the Partners relating thereto (including without limitation, the General Partner). 

(d) The General Partner may consult with legal counsel, accountants and financial or other advisors selected by it, and any act or omission
taken by the General Partner on behalf of the Partnership or in furtherance of the interests of the Partnership in good faith in 

  
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reliance upon and in accordance with the advice of such Person as to matters the General Partner reasonably believes to be within such Person’s professional or expert competence shall be
conclusively presumed to have been done or omitted in good faith and in accordance with such opinion or advice, and the General Partner will be fully protected in so acting or omitting to act so long as such counsel or accountants or financial or
other advisors were selected with reasonable care. 
 (e) Notwithstanding any other provision of this Agreement or otherwise applicable
provision of law or equity, whenever in this Agreement the General Partner is permitted or required to make a decision (i) in its “sole discretion” or “discretion” or under a grant of similar authority or latitude, such
General Partner shall be entitled to consider only such interests and factors as it desires, including its own interests, and shall, to the fullest extent permitted by applicable Law, have no duty or obligation to give any consideration to any
interest of or factors affecting the Partnership or the Limited Partners, or (ii) in its “good faith” or under another expressed standard, such General Partner shall act under such express standard and shall not be subject to any
other or different standards. 
 Section 10.02. Indemnification. 

(a) Exculpation and Indemnification. Notwithstanding any other provision of this Agreement, whether express or implied, to
the fullest extent permitted by law, no Indemnitee shall be liable to the Partnership or any Partner for any act or omission in relation to the Partnership or this Agreement or any transaction contemplated hereby taken or omitted by an Indemnitee
unless such Indemnitee’s conduct constituted fraud, bad faith or willful misconduct. To the fullest extent permitted by law, as the same exists or hereafter be amended (but in the case of any such amendment, only to the extent that such
amendment permits the Partnership to provide broader indemnification rights than such law permitted the Partnership to provide prior to such amendment), the Partnership shall indemnify any Indemnitee who was or is made or is threatened to be made a
party to or is otherwise involved in any threatened, pending or completed action, suit or proceeding (brought in the right of the Partnership or otherwise), whether civil, criminal, administrative, arbitrative or investigative, and whether formal or
informal, including appeals, by reason of his or her or its status as an Indemnitee or by reason of any action alleged to have been taken or omitted to be taken by Indemnitee in such capacity, for and against all loss and liability suffered and
expenses (including attorneys’ fees), judgments, fines and amounts paid in settlement reasonably incurred by such Indemnitee in connection with such action, suit or proceeding, including appeals; provided that such Indemnitee shall not
be entitled to indemnification hereunder if, but only to the extent that, such Indemnitee’s conduct constituted fraud, bad faith or willful misconduct. Notwithstanding the preceding sentence, except as otherwise provided in
Section 10.02(c) hereof, the Partnership shall be required to indemnify an Indemnitee in connection with any action, suit or proceeding (or part thereof) (i) commenced by such Indemnitee only if the commencement of such action, suit
or proceeding (or part thereof) by such Indemnitee was authorized by the General Partner and (ii) by or in the right of the Partnership only if the General Partner has provided its prior written consent. The indemnification of an Indemnitee of
the type identified in clause (d) of the definition of Indemnitee shall be secondary to any and all indemnification to which such Indemnitee is entitled from the relevant other Person (including any payment made to such Indemnitee under
any insurance policy issued to or for the benefit of such Person or Indemnitee) (the “Primary Indemnification”), and will only be paid to the extent the 

  
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Primary Indemnification is not paid and/or does not provide coverage (e.g., a self-insured retention amount under an insurance policy). No such Person shall be entitled to contribution or
indemnification from or subrogation against the Partnership. The indemnification of any other Indemnitee shall, to the extent not in conflict with such policy, be secondary to any and all payment to which such Indemnitee is entitled from any
relevant insurance policy issued to or for the benefit of the Partnership or any Indemnitee. For the avoidance of doubt, this Agreement shall not affect the indemnification and advancement rights provided pursuant to the Original Agreement in favor
of any Person relating to proceedings arising out of actions or omissions occurring in whole or in part prior to the effectiveness of this Agreement. 

(b) Advancement of Expenses. To the fullest extent permitted by law, the Partnership shall promptly pay expenses
(including attorneys’ fees) incurred by any Indemnitee in appearing at, participating in or defending any action, suit or proceeding in advance of the final disposition of such action, suit or proceeding, including appeals, upon presentation of
an undertaking on behalf of such Indemnitee to repay such amount if it shall ultimately be determined that such Indemnitee is not entitled to be indemnified under this Section 10.02 or otherwise. Notwithstanding the preceding sentence,
except as otherwise provided in Section 10.02(c) hereof, the Partnership shall be required to pay expenses of an Indemnitee in connection with any action, suit or proceeding (or part thereof) (i) commenced by such Indemnitee only if
the commencement of such action, suit or proceeding (or part thereof) by such Indemnitee was authorized by the General Partner and (ii) by or in the right of the Partnership only if the General Partner has provided its prior written consent.

 (c) Unpaid Claims. If a claim for indemnification (following the final disposition of such action, suit or
proceeding) or advancement of expenses under this Section 10.02 is not paid in full within thirty (30) days after a written claim therefor by any Indemnitee has been received by the Partnership, such Indemnitee may file proceedings
to recover the unpaid amount of such claim and, if successful in whole or in part, shall be entitled to be paid the expense of prosecuting such claim. In any such action the Partnership shall have the burden of proving that such Indemnitee is not
entitled to the requested indemnification or advancement of expenses under applicable Law. 
 (d) Insurance. (i)
To the fullest extent permitted by law, the Partnership may purchase and maintain insurance on behalf of any person described in Section 10.02(a) hereof against any liability asserted against such person, whether or not the Partnership
would have the power to indemnify such person against such liability under the provisions of this Section 10.02 or otherwise. 

(ii) In the event of any payment by the Partnership under this Section 10.02, the Partnership shall be subrogated to the extent
of such payment to all of the rights of recovery of the Indemnitee from any relevant other Person or under any insurance policy issued to or for the benefit of the Partnership, such relevant other Person, or any Indemnitee. Each Indemnitee agrees to
execute all papers required and take all action necessary to secure such rights, including the execution of such documents as are necessary to enable the Partnership to bring suit to enforce any such rights in accordance with the terms of such
insurance policy or other relevant document. The Partnership shall pay or reimburse all expenses actually and reasonably incurred by the Indemnitee in connection with such subrogation. 

  
 30 

 (iii) The Partnership shall not be liable under this Section 10.02 to make any
payment of amounts otherwise indemnifiable hereunder (including, but not limited to, judgments, fines and amounts paid in settlement, and excise taxes with respect to an employee benefit plan or penalties) if and to the extent that the applicable
Indemnitee has otherwise actually received such payment under this Section 10.02 or any insurance policy, contract, agreement or otherwise. 

(e) Non-Exclusivity of Rights. The provisions of this Section 10.02 shall be applicable to all actions,
claims, suits or proceedings made or commenced after the date of this Agreement, whether arising from acts or omissions to act occurring before or after its adoption. The provisions of this Section 10.02 shall be deemed to be a contract
between the Partnership and each person entitled to indemnification under this Section 10.02 (or legal representative thereof) who serves in such capacity at any time while this Section 10.02 and the relevant provisions of
applicable Law, if any, are in effect, and any amendment, modification or repeal hereof shall not affect any rights or obligations then existing with respect to any state of facts or any action, suit or proceeding then or theretofore existing, or
any action, suit or proceeding thereafter brought or threatened based in whole or in part on any such state of facts. If any provision of this Section 10.02 shall be found to be invalid or limited in application by reason of any law or
regulation, it shall not affect the validity of the remaining provisions hereof. The rights of indemnification provided in this Section 10.02 shall neither be exclusive of, nor be deemed in limitation of, any rights to which any person
may otherwise be or become entitled or permitted by contract, this Agreement or as a matter of law, both as to actions in such person’s official capacity and actions in any other capacity, it being the policy of the Partnership that
indemnification of any person whom the Partnership is obligated to indemnify pursuant to Section 10.02(a) hereof shall be made to the fullest extent permitted by law. 

For purposes of this Section 10.02, references to “other enterprises” shall include employee benefit plans; references
to “fines” shall include any excise taxes assessed on a person with respect to an employee benefit plan; and references to “serving at the request of the Partnership” shall include any service as a director, officer, employee or
agent of the Partnership which imposes duties on, or involves services by, such director, officer, employee, or agent with respect to an employee benefit plan, its participants, or beneficiaries. 

This Section 10.02 shall not limit the right of the Partnership, to the extent and in the manner permitted by law, to indemnify
and to advance expenses to, and purchase and maintain insurance on behalf of, persons other than persons described in Section 10.02(a) hereof. 

ARTICLE XI 

MISCELLANEOUS 
 Section
11.01. Severability. If any term or other provision of this Agreement is held to be invalid, illegal or incapable of being enforced by any rule of Law, or public policy, all other conditions and provisions of this Agreement shall
nevertheless remain in full force and effect so long as the economic or legal substance of the transactions is not affected in any manner materially adverse to any party. Upon a determination that any term or other provision is invalid, illegal or
incapable of being enforced, the parties hereto shall negotiate in good faith to modify this 

  
 31 

 
Agreement so as to effect the original intent of the parties as closely as possible in a mutually acceptable manner in order that the transactions contemplated hereby be consummated as originally
contemplated to the fullest extent possible. 
 Section 11.02. Notices. All notices, requests, claims, demands and
other communications hereunder shall be in writing and shall be given (and shall be deemed to have been duly given upon receipt) by delivery in person, by courier service (delivery receipt requested), by fax, by electronic mail or by registered or
certified mail (postage prepaid, return receipt requested) to the respective parties at the following addresses (or at such other address for a party as shall be specified in a notice given in accordance with this Section 11.02): 

 

	 	(a)	If to the Partnership, to: 

 Summit Materials Holdings L.P. 

1550 Wynkoop Street, 3rd Floor 

Denver, Colorado 80202 

Attention: Chief Legal Officer 

Fax: (303) 893-6993 

Email: Legal@Summit-Materials.com 

with a copy to: 
 Summit
Materials Holdings L.P. 
 1550 Wynkoop Street, 3rd Floor 

Denver, Colorado 80202 

Attention: [Chief Financial Officer] 

Fax: [            ] 

Email: [Brian.Harris@summit-materials.com] 
  

	 	(b)	If to any Limited Partner, to: 

 c/o Summit Materials Holdings L.P. 

1550 Wynkoop Street, 3rd Floor 

Denver, Colorado 80202 

Attention: Chief Legal Officer 

Fax: (303) 893-6993 

Email: Legal@Summit-Materials.com 

with a copy to: 
 c/o Summit
Materials Holdings L.P. 
 1550 Wynkoop Street, 3rd Floor 

Denver, Colorado 80202 

Attention: [Chief Financial Officer] 

Fax: [            ] 

Email: [Brian.Harris@summit-materials.com] 

  
 32 

 The General Partner shall use commercially reasonable efforts to forward any such communication
to the applicable Partner’s address, email address or facsimile number as shown in the Partnership’s books and records. 
  

	 	(c)	If to the General Partner, to: 

 Summit Materials, Inc. 

1550 Wynkoop Street, 3rd Floor 

Denver, Colorado 80202 

Attention: Chief Legal Officer 

Fax: (303) 893-6993 

Email: Legal@Summit-Materials.com 

with a copy to: 
 Summit
Materials, Inc. 
 1550 Wynkoop Street, 3rd Floor 

Denver, Colorado 80202 

Attention: [Chief Financial Officer] 

Fax: [            ] 

Email: [Brian.Harris@summit-materials.com] 

Section 11.03. Cumulative Remedies. The rights and remedies provided by this Agreement are cumulative and the use of any
one right or remedy by any party shall not preclude or waive its right to use any or all other remedies. Said rights and remedies are given in addition to any other rights the parties may have by Law. 

Section 11.04. Binding Effect. This Agreement shall be binding upon and inure to the benefit of all of the parties and, to
the extent permitted by this Agreement, their successors, executors, administrators, heirs, legal representatives and assigns. 
 Section
11.05. Interpretation. Throughout this Agreement, nouns, pronouns and verbs shall be construed as masculine, feminine, neuter, singular or plural, whichever shall be applicable. Unless otherwise specified, all references
herein to “Articles,” “Sections” and paragraphs shall refer to corresponding provisions of this Agreement. 
 Each party
hereto acknowledges and agrees that the parties hereto have participated collectively in the negotiation and drafting of this Agreement and that he or she or it has had the opportunity to draft, review and edit the language of this Agreement;
accordingly, it is the intention of the parties that no presumption for or against any party arising out of drafting all or any part of this Agreement will be applied in any dispute relating to, in connection with or involving this Agreement.
Accordingly, the parties hereby waive to the fullest extent permitted by law the benefit of any rule of law or any legal decision that would require that in cases of uncertainty, the language of a contract should be interpreted most strongly against
the party who drafted such language. 
 Section 11.06. Counterparts. This Agreement may be executed and delivered
(including by facsimile transmission) in one or more counterparts, and by the different parties hereto in separate counterparts, each of which when executed and delivered shall be deemed to be 

  
 33 

 
an original but all of which taken together shall constitute one and the same agreement. Copies of executed counterparts transmitted by telecopy or other electronic transmission service shall be
considered original executed counterparts for purposes of this Section 11.06. 
 Section 11.07. Further
Assurances. Each Partner shall perform all other acts and execute and deliver all other documents as may be necessary or appropriate to carry out the purposes and intent of this Agreement. 

Section 11.08. Entire Agreement. This Agreement constitutes the entire agreement among the parties hereto pertaining
to the subject matter hereof and supersedes all prior agreements and understandings pertaining thereto. 
 Section 11.09. Governing
Law. This Agreement shall be governed by, and construed in accordance with, the law of the State of Delaware. 

Section 11.10. Submission to Jurisdiction; Waiver of Jury Trial. 

(a) Any and all disputes which cannot be settled amicably, including any ancillary claims of any party, arising out of, relating to or in
connection with the validity, negotiation, execution, interpretation, performance or non-performance of this Agreement (including the validity, scope and enforceability of this arbitration provision) shall be
finally settled by arbitration conducted by a single arbitrator in New York in accordance with the then-existing Rules of Arbitration of the International Chamber of Commerce. If the parties to the dispute
fail to agree on the selection of an arbitrator within thirty (30) days of the receipt of the request for arbitration, the International Chamber of Commerce shall make the appointment. The arbitrator shall be a lawyer and shall conduct the
proceedings in the English language. Performance under this Agreement shall continue if reasonably possible during any arbitration proceedings. 

(b) Notwithstanding the provisions of Section 11.10(a) hereof, the parties hereto may bring an action or special proceeding in any
court of competent jurisdiction for the purpose of compelling a party to arbitrate, seeking temporary or preliminary relief in aid of an arbitration hereunder, and/or enforcing an arbitration award and, for the purposes of this
Section 11.10(b), each party hereto (i) expressly consents to the application of Section 11.10(c) hereof to any such action or proceeding and (ii) agrees that proof shall not be required that monetary damages for
breach of the provisions of this Agreement would be difficult to calculate and that remedies at law would be inadequate. 
 (c) (i) EACH
PARTY HERETO IRREVOCABLY SUBMITS TO THE JURISDICTION OF COURTS LOCATED IN NEW YORK, NEW YORK FOR THE PURPOSE OF ANY JUDICIAL PROCEEDING BROUGHT IN ACCORDANCE WITH THE PROVISIONS OF THIS SECTION 11.10, OR ANY JUDICIAL PROCEEDING ANCILLARY TO
AN ARBITRATION OR CONTEMPLATED ARBITRATION ARISING OUT OF OR RELATING TO OR CONCERNING THIS AGREEMENT. Such ancillary judicial proceedings include any suit, action or proceeding to compel arbitration, to obtain temporary or preliminary judicial
relief in aid of arbitration, or to confirm an arbitration award. The parties acknowledge that the fora designated by this Section 11.10(c) have a reasonable relation to this Agreement, and to the parties’ relationship with one
another. 

  
 34 

 (ii) The parties hereby waive, to the fullest extent permitted by applicable law, any objection
which they now or hereafter may have to personal jurisdiction or to the laying of venue of any such ancillary suit, action or proceeding brought in any court referred to in the preceding paragraph of this Section 11.10 and such parties
agree not to plead or claim the same. 
 Section 11.11. Expenses. Except as otherwise specified in this Agreement,
the Partnership shall be responsible for all costs and expenses, including, without limitation, fees and disbursements of counsel, financial advisors and accountants, incurred in connection with its operation. 

Section 11.12. Amendments and Waivers 

(a) This Agreement (including the Annexes hereto) may be amended, supplemented, waived or modified by the General Partner in its sole
discretion without the approval of any Limited Partner or other Person; provided that for so long as Blackstone Limited Partners collectively own, in the aggregate, at least 5% of the outstanding Class A Units, the prior written consent
of each Blackstone Limited Partner will be required for any amendment, supplement, waiver or modification of this Agreement, including any amendment, supplement, waiver or modification that may occur as a result of merger, consolidation, combination
or conversion of the Partnership; provided further that no amendment may materially and adversely affect the rights of a holder of Units, as such, other than on a pro rata basis with other holders of Units of the same Class without the
consent of such holder (or, if there is more than one such holder that is so affected, without the consent of a majority in interest of such affected holders in accordance with their holdings of such Class of Units); provided, however,
that notwithstanding the foregoing, the General Partner may, without the written consent of any Limited Partner or any other Person, amend, supplement, waive or modify any provision of this Agreement and execute, swear to, acknowledge, deliver, file
and record whatever documents may be required in connection therewith, to reflect: (1) any amendment, supplement, waiver or modification that the General Partner determines in its sole discretion to be necessary or appropriate in connection
with the creation, authorization or issuance of Units or any Class or series of equity interest in the Partnership pursuant to Section 7.01 hereof; (2) the admission, substitution, withdrawal or removal of Partners in accordance
with this Agreement, including pursuant to Section 7.01 hereof; (3) a change in the name of the Partnership, the location of the principal place of business of the Partnership, the registered agent of the Partnership or the
registered office of the Partnership; (4) any amendment, supplement, waiver or modification that the General Partner determines in its sole discretion to be necessary or appropriate to address changes in U.S. federal income tax regulations,
legislation or interpretation; and/or (5) a change in the Fiscal Year or taxable year of the Partnership and any other changes that the General Partner determines to be necessary or appropriate as a result of a change in the Fiscal Year or
taxable year of the Partnership including a change in the dates on which distributions are to be made by the Partnership. If an amendment has been approved in accordance with this agreement, such amendment shall be adopted and effective with respect
to all Partners. Upon obtaining such approvals as may be required by this Agreement, and without further action or execution on the part of any other Partner or other Person, any amendment to this Agreement may be implemented and reflected in a
writing executed solely by the General Partner and the Limited Partners shall be deemed a party to and bound by such amendment. 

  
 35 

 (b) No failure or delay by any party in exercising any right, power or privilege hereunder (other
than a failure or delay beyond a period of time specified herein) shall operate as a waiver thereof nor shall any single or partial exercise thereof preclude any other or further exercise thereof or the exercise of any other right, power or
privilege. The rights and remedies herein provided shall be cumulative and not exclusive of any rights or remedies provided by Law. 
 (c)
The General Partner may, in its sole discretion, unilaterally amend this Agreement on or before the effective date of the final regulations to provide for (i) the election of a safe harbor under Proposed Treasury Regulation
Section 1.83-3(l) (or any similar provision) under which the fair market value of a Partnership interest (or interest in an entity treated as a partnership for U.S. federal income tax purposes) that is transferred is treated as being equal to
the liquidation value of that interest, (ii) an agreement by the Partnership and each of its Partners to comply with all of the requirements set forth in such regulations and Notice 2005-43 (and any other guidance provided by the Internal
Revenue Service with respect to such election) with respect to all Partnership interests (or interest in an entity treated as a partnership for U.S. federal income tax purposes) transferred in connection with the performance of services while the
election remains effective, (iii) the allocation of items of income, gains, deductions and losses required by the final regulations similar to Proposed Treasury Regulation Section 1.704-1(b)(4)(xii)(b) and (c), 1.704-1(b)(2)(iv)(b)(1) and
any other related amendments. 
 (d) Except as may be otherwise required by law in connection with the winding-up, liquidation, or
dissolution of the Partnership, each Partner hereby irrevocably waives any and all rights that it may have to maintain an action for judicial accounting or for partition of any of the Partnership’s property. 

Section 11.13. No Third Party Beneficiaries. This Agreement shall be binding upon and inure solely to the benefit of
the parties hereto and their permitted assigns and successors and nothing herein, express or implied, is intended to or shall confer upon any other Person or entity, any legal or equitable right, benefit or remedy of any nature whatsoever under or
by reason of this Agreement (other than pursuant to Section 10.02 hereof); provided, however, that each employee, officer, director, agent or indemnitee of any Person who is bound by this Agreement or its Affiliates is an
intended third party beneficiary of Section 11.10 hereof and shall be entitled to enforce its rights thereunder. 
 Section
11.14. Headings. The headings and subheadings in this Agreement are included for convenience and identification only and are in no way intended to describe, interpret, define or limit the scope, extent or intent of this
Agreement or any provision hereof. 
 Section 11.15. Power of Attorney. Each Limited Partner hereby irrevocably
makes, constitutes and appoints the General Partner as its true and lawful agent and attorney in fact, with full power of substitution and full power and authority in its name, place and stead, to make, execute, sign, acknowledge, swear to, record
and file (a) this Agreement and any amendment to this Agreement that has been adopted as herein provided; (b) all amendments to the Certificate required or permitted by law or the provisions of this Agreement; (c) all certificates and
other instruments (including consents and ratifications which the Limited Partners have agreed to provide upon a matter receiving the agreed support of Limited Partners) deemed advisable by the General Partner to carry out the provisions of this
Agreement (including the provisions of Section 8.04 hereof) and 

  
 36 

 
Law or to permit the Partnership to become or to continue as a limited partnership or entity wherein the Limited Partners have limited liability in each jurisdiction where the Partnership may be
doing business; (d) all instruments that the General Partner deems appropriate to reflect a change or modification of this Agreement or the Partnership in accordance with this Agreement, including, without limitation, the admission of
additional Limited Partners or substituted Limited Partners pursuant to the provisions of this Agreement; (e) all conveyances and other instruments or papers deemed advisable by the General Partner to effect the liquidation and termination of
the Partnership; and (f) all fictitious or assumed name certificates required or permitted (in light of the Partnership’s activities) to be filed on behalf of the Partnership. 

Section 11.16. Separate Agreements; Schedules. Notwithstanding any other provision of this Agreement, including
Section 11.12 hereof, the General Partner in its sole discretion may, or may cause the Partnership to, without the approval of any Limited Partner or other Person, enter into separate subscription, letter or other agreements with
individual Limited Partners with respect to any matter, which have the effect of establishing rights under, or altering, supplementing or amending the terms of, this Agreement. The parties hereto agree that any terms contained in any such separate
agreement shall govern with respect to such Limited Partner(s) party thereto notwithstanding the provisions of this Agreement. The General Partner in its sole discretion may from time to time execute and deliver to the Limited Partners schedules
which set forth information contained in the books and records of the Partnership and any other matters deemed appropriate by the General Partner. Such schedules shall be for information purposes only and shall not be deemed to be part of this
Agreement for any purpose whatsoever. Notwithstanding anything to the contrary, solely for U.S. federal income tax purposes, this Agreement and the Exchange Agreement, and any other separate agreement described in this Section 11.16 shall each
constitute a “partnership agreement” within the meaning of Section 761(c) of the Code and Sections 1.704-1(b)(2)(ii)(h) and 1.761-1(c) of the Treasury Regulations. 

Section 11.17. Partnership Status. The Partners intend for the Partnership to be treated as a partnership for U.S.
federal income tax purposes and notwithstanding anything to the contrary herein, no election to the contrary shall be made. 
 Section
11.18. Delivery by Facsimile or Email. This Agreement, the agreements referred to herein, and each other agreement or instrument entered into in connection herewith or therewith or contemplated hereby or thereby, and any amendments
hereto or thereto, to the extent signed and delivered by means of a facsimile machine or email with scan or facsimile attachment, shall be treated in all manner and respects as an original agreement or instrument and shall be considered to have the
same binding legal effect as if it were the original signed version thereof delivered in person. No party hereto or to any such agreement or instrument shall raise the use of a facsimile machine or email to deliver a signature or the fact that any
signature or agreement or instrument was transmitted or communicated through the use of a facsimile machine or email as a defense to the formation or enforceability of a contract, and each such party forever waives any such defense. 

Section 11.19. Non-Occurrence of IPO. Notwithstanding any other provision of this Agreement (including
Section 11.12), in the event that the IPO of the Class A common stock of the General Partner is not consummated prior to the date that is ten (10) business days after the date of this Agreement, then this Agreement shall
automatically, with no action required by any Partner, 

  
 37 

 
on such date be amended and restated in its entirety back to the Original Agreement and upon such automatic amendment and restatement of this Agreement, this Agreement shall be of no force and
effect. For the avoidance of doubt, in the event that the IPO is not consummated, the outstanding interests in the Partnership converted into Class A Units in accordance with the IPO Reorganization Agreement will automatically, with no action
required by an Partner, on such date be considered null and void, and such converted interests shall be reinstated in their entirety pursuant to the Original Agreement. Notwithstanding any other provision of this Agreement (including
Section 11.12), this Section 11.19 may not be amended prior to the consummation of the IPO of the Class A common stock of the General Partner. 

[Remainder of Page Intentionally Left Blank] 

  
 38 

 IN WITNESS WHEREOF, the parties hereto have entered into this Agreement or have caused this
Agreement to be duly executed by their respective authorized officers, in each case as of the date first above stated. 
  

			
	General Partner:
	
	SUMMIT MATERIALS, INC.
		
	By:	 	 
	 Name:
 Title:
	 	 Thomas W. Hill
 Chief Executive
Officer

 [Signature Page to Fourth Amended and Restated Limited Partnership Agreement of Summit Materials Holdings
L.P.] 

 
			
	Blackstone Limited Partners:
	
	 BLACKSTONE PARTICIPATION PARTNERSHIP

(CAYMAN) V-NQ L.P.

		
	By:	 	BCP V-NQ GP L.L.C., its U.S. general partner

  

			
	By:	 	 
	 Name:

Title:
	 	 Neil P. Simpkins
 Senior Managing
Director

	
	 Witnessed by:

		
	 	 	 
	 Name:
	 	
	 Title:
	 	
	
	 BLACKSTONE FAMILY INVESTMENT

PARTNERSHIP (CAYMAN) V-NQ L.P.

  

			
	By:	 	BCP V-NQ GP L.L.C., its U.S. general partner

  

			
		
	By:	 	 
	Name:	 	Neil P. Simpkins
	 Title:
	 	Senior Managing Director

  

			
	Witnessed by:
		
	 	 	 
	Name:	 	
	Title:	 	

 
			
	BLACKSTONE CAPITAL PARTNERS (CAYMAN) V-NQ L.P.
	
	By:    Blackstone Management Associates (Cayman) V-NQ L.P., its general partner
	
	By:    BCP V-NQ GP L.L.C., its U.S. general partner
		
	By:	 	 
	Name:	 	Neil P. Simpkins
	Title:	 	Senior Managing Director
	
	Witnessed by:
	
	  

	Name:	 	
	Title:	 	
	
	BLACKSTONE CAPITAL PARTNERS (CAYMAN) NQ V-AC L.P.
	
	By:    Blackstone Management Associates (Cayman) V-NQ L.P., its general partner
	
	By:    BCP V-NQ GP L.L.C., its U.S. general partner
		
	By:	 	 
	Name:	 	Neil P. Simpkins
	Title:	 	Senior Managing Director
	
	Witnessed by:
	
	  

	Name:	 	
	Title:	 	

 
			
	SUMMIT BCP INTERMEDIATE HOLDINGS L.P.
	
	By:     Summit BCP Intermediate Holdings GP, Ltd., its general partner
		
	By:	 	 
	Name:	 	Neil P. Simpkins
	Title:	 	Authorized Person

 
			
	Silverhawk Limited Partners:
	
	SILVERHAWK SUMMIT, L.P.
	
	By:    Silverhawk Capital Partners GP II, L.P., its general partner
		
	By:	 	 
	Name:
	Title:

  

			
	Witnessed by:
	
	 
	Name:
	Title:

 
			
	Thomas W. Hill:
		
	By:	 	 
	Name: Thomas W. Hill

  

			
	Witnessed by:
	
	 
	Name:	 	
	Title:	 	

 
			
	Limited Partners:
	
	All Limited Partners listed in the register of the Partnership as of the date hereof (other than those Limited Partners who signed on their own behalf above).
	
	By:    Summit Materials Holdings GP, Ltd., as attorney-in-fact
		
	By:	 	 
	Name:
	Title:

 The undersigned hereby acknowledge that, in accordance with Section 2.08 of this Agreement, Summit
Owner Holdco LLC shall replace Summit Materials Holdings GP, LTD as an interim general partner simultaneously with the consummation of the IPO and that immediately thereafter Summit Materials, Inc. shall replace Summit Owner Holdco LLC as general
partner of the Partnership. 
  

			
	SUMMIT MATERIALS HOLDINGS GP, LTD.
		
	By:	 	 
	Name:
	Title:

  

			
	SUMMIT OWNER HOLDCO LLC
	
	By:    Summit Materials Holdings GP, Ltd., its managing member
		
	By:	 	 
	Name:
	Title:EX-10.2

 Exhibit 10.2 

TAX RECEIVABLE AGREEMENT 

between 
 SUMMIT
MATERIALS, INC. 
 and 

THE PERSONS NAMED HEREIN 

Dated as of [            ], 2015 

 TABLE OF CONTENTS 
  

							
	 	 	 	  	Page	 
	 ARTICLE I DEFINITIONS
	  	 	2	  
			
	 Section 1.1
	 	Definitions	  	 	2	  
		
	ARTICLE II DETERMINATION OF CERTAIN REALIZED TAX BENEFIT	  	 	10	  
			
	 Section 2.1
	 	Basis Adjustment	  	 	10	  
	 Section 2.2
	 	Tax Benefit Schedule	  	 	10	  
	 Section 2.3
	 	Procedures, Amendments	  	 	11	  
		
	ARTICLE III TAX BENEFIT PAYMENTS	  	 	12	  
			
	 Section 3.1
	 	Payments	  	 	12	  
	 Section 3.2
	 	No Duplicative Payments	  	 	14	  
	 Section 3.3
	 	Pro Rata Payments	  	 	14	  
		
	ARTICLE IV TERMINATION	  	 	14	  
			
	 Section 4.1
	 	Early Termination of Agreement; Breach of Agreement	  	 	14	  
	 Section 4.2
	 	Early Termination Notice	  	 	16	  
	 Section 4.3
	 	Payment upon Early Termination	  	 	16	  
		
	ARTICLE V SUBORDINATION AND LATE PAYMENTS	  	 	17	  
			
	 Section 5.1
	 	Subordination	  	 	17	  
	 Section 5.2
	 	Late Payments by the Corporate Taxpayer	  	 	17	  
		
	ARTICLE VI NO DISPUTES; CONSISTENCY; COOPERATION	  	 	17	  
			
	 Section 6.1
	 	Participation in the Corporate Taxpayer’s and OpCo’s Tax Matters	  	 	17	  
	 Section 6.2
	 	Consistency	  	 	18	  
	 Section 6.3
	 	Cooperation	  	 	18	  
		
	ARTICLE VII MISCELLANEOUS	  	 	18	  
			
	 Section 7.1
	 	Notices	  	 	18	  
	 Section 7.2
	 	Counterparts	  	 	19	  
	 Section 7.3
	 	Entire Agreement; No Third Party Beneficiaries	  	 	19	  
	 Section 7.4
	 	Governing Law	  	 	19	  
	 Section 7.5
	 	Severability	  	 	19	  
	 Section 7.6
	 	Successors; Assignment; Amendments; Waivers	  	 	19	  
	 Section 7.7
	 	Titles and Subtitles	  	 	20	  
	 Section 7.8
	 	Resolution of Disputes	  	 	20	  
	 Section 7.9
	 	Reconciliation	  	 	21	  
	 Section 7.10
	 	Withholding	  	 	22	  
	 Section 7.11
	 	Admission of the Corporate Taxpayer into a Consolidated Group; Transfers of Corporate Assets	  	 	22	  
	 Section 7.12
	 	Confidentiality	  	 	23	  
	 Section 7.13
	 	Change in Law	  	 	23	  

  
 i 

 TAX RECEIVABLE AGREEMENT 

This TAX RECEIVABLE AGREEMENT (this “Agreement”), is dated as of
[            ], 2015, and is between Summit Materials, Inc., a Delaware corporation (including any successor corporation, the “Corporate Taxpayer”), each of the
undersigned parties, and each of the other persons from time to time party hereto (each a “TRA Party” and together the “TRA Parties”). 

RECITALS 
 WHEREAS,
the TRA Parties (other than the Existing Shareholders Representative (as defined below)) directly or indirectly hold limited partner interests (the “Units”) in Summit Materials Holdings L.P., a Delaware limited partnership
(“OpCo”), which is classified as a partnership for United States federal income tax purposes; 
 WHEREAS, the
Corporate Taxpayer is the general partner of OpCo, and holds and will hold, directly and/or indirectly, Units; 
 WHEREAS, the Units
held by the TRA Parties may be exchanged for Class A common stock (the “Class A Shares”) of the Corporate Taxpayer, in accordance with and subject to the provisions of the LP Agreement (as defined below) and the Exchange
Agreement (as defined below), dated as of [            ], 2015, between the Corporate Taxpayer, OpCo and the holders of Units from time to time party thereto; 

WHEREAS, OpCo and each of its direct and indirect Subsidiaries (as defined below) treated as a partnership for United States federal
income tax purposes currently have and will have in effect an election under Section 754 of the United States Internal Revenue Code of 1986, as amended (the “Code”), for each Taxable Year (as defined below) in which a
taxable acquisition (including a deemed taxable acquisition under Section 707(a) of the Code) of Units by the Corporate Taxpayer from any of the TRA Parties for Class A Shares or other consideration (an “Exchange”)
occurs;  
 WHEREAS, the income, gain, loss, expense and other Tax (as defined below) items of the Corporate Taxpayer may be
affected by the Basis Adjustments (as defined below) and the Imputed Interest (as defined below); 
 WHEREAS, the parties to this
Agreement desire to make certain arrangements with respect to the effect of the Basis Adjustments and Imputed Interest on the liability for Taxes of the Corporate Taxpayer; 

WHEREAS, Exchanges by the TRA Parties and payments in respect of Tax savings related to such Exchanges are expected to result in Tax
savings for the Corporate Taxpayer; and 
 WHEREAS, the Corporate Taxpayer may achieve Tax savings as a result of becoming entitled
to Pre-Merger NOLs of a Blocker TRA Party upon completion of any Blocker TRA Party Merger (each as defined below). 

  
 1 

 NOW, THEREFORE, in consideration of the foregoing and the respective covenants and
agreements set forth herein, and intending to be legally bound hereby, the parties hereto agree as follows: 
 ARTICLE I 

DEFINITIONS 

Section 1.1 Definitions. As used in this Agreement, the terms set forth in this Article I shall have the following meanings
(such meanings to be equally applicable to both the singular and plural forms of the terms defined). 
 “Affiliate”
means, with respect to any Person, any other Person that directly or indirectly, through one or more intermediaries, Controls, is Controlled by, or is under common Control with, such first Person.  

“Agreed Rate” means LIBOR plus 100 basis points. 

“Agreement” is defined in the Preamble to this Agreement. 

“Amended Schedule” is defined in Section 2.3(b) of this Agreement. 

“Basis Adjustment” means the adjustment to the tax basis of a Reference Asset under Sections 732, 734(b) and 1012 of
the Code (in situations where, as a result of one or more Exchanges, OpCo becomes an entity that is disregarded as separate from its owner for United States federal income tax purposes) or under Sections 734(b), 743(b) and 754 of the Code (in
situations where, following an Exchange, OpCo remains in existence as an entity treated as a partnership for United States federal income tax purposes) and, in each case, comparable sections of state and local tax laws, as a result of an Exchange
and the payments made pursuant to this Agreement. For the avoidance of doubt, the amount of any Basis Adjustment resulting from an Exchange of one or more Units shall be determined without regard to any Pre-Exchange Transfer of such Units and as if
any such Pre-Exchange Transfer had not occurred. 
 A “Beneficial Owner” of a security is a Person who directly or
indirectly, through any contract, arrangement, understanding, relationship or otherwise, has or shares: (i) voting power, which includes the power to vote, or to direct the voting of, such security; and/or (ii) investment power, which
includes the power to dispose of, or to direct the disposition of, such security. The terms “Beneficially Own” and “Beneficial Ownership” shall have correlative meanings. 

“Blocker TRA Parties” means Blackstone SMT Feeder Fund V L.P., a Delaware limited partnership, Blackstone SMT Feeder
Fund (Cayman) V L.P., a Cayman Islands limited partnership, Blackstone SMT Feeder Fund V-AC, a Delaware limited partnership and Blackstone SMT Feeder Fund (Cayman) V-AC L.P., a Cayman Islands limited partnership. 

“Blocker TRA Party Merger” means either the merger of a Blocker TRA Party with and into the Corporate Taxpayer, with
the Corporate Taxpayer surviving, or the contribution of all of the stock of a Blocker TRA Party to the Corporate Taxpayer in exchange for stock of the Corporate Taxpayer. 

  
 2 

 “Board” means the Board of Directors of the Corporate Taxpayer. 

 “Business Day” means Monday through Friday of each week, except that a legal holiday recognized as such by the
government of the United States of America or the State of New York shall not be regarded as a Business Day. 
 “Change of
Control” means the occurrence of any of the following events: 
  

	 	(i)	any Person or any group of Persons acting together that would constitute a “group” for purposes of Section 13(d) of the Securities and Exchange Act of 1934, or any successor provisions thereto (excluding
(a) a corporation or other entity owned, directly or indirectly, by the stockholders of the Corporate Taxpayer in substantially the same proportions as their ownership of stock of the Corporate Taxpayer or (b) a group of Persons in which
one or more Affiliates of Permitted Investors, directly or indirectly hold Beneficial Ownership of securities representing more than 50% of the total voting power held by such group) is or becomes the Beneficial Owner, directly or indirectly, of
securities of the Corporate Taxpayer representing more than 50% of the combined voting power of the Corporate Taxpayer’s then outstanding voting securities; or 

 

	 	(ii)	the following individuals cease for any reason to constitute a majority of the number of directors of the Corporate Taxpayer then serving: individuals who, on the IPO Date, constitute the Board and any new director
whose appointment or election by the Board or nomination for election by the Corporate Taxpayer’s shareholders was approved or recommended by a vote of at least two-thirds (2/3) of the directors then still in office who either were
directors on the IPO Date or whose appointment, election or nomination for election was previously so approved or recommended by the directors referred to in this clause (ii); or 

 

	 	(iii)	there is consummated a merger or consolidation of the Corporate Taxpayer with any other corporation or other entity, and, immediately after the consummation of such merger or consolidation, either (x) the Board
immediately prior to the merger or consolidation does not constitute at least a majority of the board of directors of the company surviving the merger or, if the surviving company is a Subsidiary, the ultimate parent thereof, or (y) the voting
securities of the Corporate Taxpayer immediately prior to such merger or consolidation do not continue to represent or are not converted into more than 50% of the combined voting power of the then outstanding voting securities of the Person
resulting from such merger or consolidation or, if the surviving company is a Subsidiary, the ultimate parent thereof; or 

  
 3 

	 	(iv)	the shareholders of the Corporate Taxpayer approve a plan of complete liquidation or dissolution of the Corporate Taxpayer or there is consummated an agreement or series of related agreements for the sale, lease or
other disposition, directly or indirectly, by the Corporate Taxpayer of all or substantially all of the Corporate Taxpayer’s assets, other than such sale or other disposition by the Corporate Taxpayer of all or substantially all of the
Corporate Taxpayer’s assets to an entity at least 50% of the combined voting power of the voting securities of which are owned by shareholders of the Corporate Taxpayer in substantially the same proportions as their ownership of the Corporate
Taxpayer immediately prior to such sale. 

 Notwithstanding the foregoing, except with respect to clause (ii) and clause (iii)(x) above,
a “Change of Control” shall not be deemed to have occurred by virtue of the consummation of any transaction or series of integrated transactions immediately following which the record holders of the shares of the Corporate Taxpayer
immediately prior to such transaction or series of transactions continue to have substantially the same proportionate ownership in, and own substantially all of the shares of, an entity which owns all or substantially all of the assets of the
Corporate Taxpayer immediately following such transaction or series of transactions. 
 “Class A Shares” is defined
in the Recitals of this Agreement. 
 “Code” is defined in the Recitals of this Agreement. 

“Control” means the possession, direct or indirect, of the power to direct or cause the direction of the management
and policies of a Person, whether through ownership of voting securities, by contract or otherwise. 
 “Corporate
Taxpayer” is defined in the Preamble to this Agreement; provided that the term “Corporate Taxpayer” shall include any company that is a member of any consolidated tax return of which Summit Materials, Inc. is the common
parent, where appropriate. 
 “Corporate Taxpayer Return” means the federal and/or state and/or local Tax Return, as
applicable, of the Corporate Taxpayer filed with respect to Taxes of any Taxable Year. 
 “Cumulative Net Realized Tax
Benefit” for a Taxable Year means the cumulative amount of Realized Tax Benefits for all Taxable Years of the Corporate Taxpayer, up to and including such Taxable Year, net of the cumulative amount of Realized Tax Detriments for the
same period. The Realized Tax Benefit and Realized Tax Detriment for each Taxable Year shall be determined based on the most recent Tax Benefit Schedules or Amended Schedules, if any, in existence at the time of such determination. 

“Cumulative NOL Net Realized Tax Benefit” for a Taxable Year means the cumulative amount of NOL Realized Tax Benefits
for all Taxable Years of the Corporate Taxpayer, up to and including such Taxable Year. The NOL Realized Tax Benefit for each 

  
 4 

 
Taxable Year shall be determined based on the most recent Tax Benefit Schedules or Amended Schedules, if any, in existence at the time of such determination. 

“Default Rate” means LIBOR plus 500 basis points. 

“Determination” shall have the meaning ascribed to such term in Section 1313(a) of the Code or similar provision
of state, foreign or local tax law, as applicable, or any other event (including the execution of IRS Form 870-AD) that finally and conclusively establishes the amount of any liability for Tax. 

“Dispute” has the meaning set forth in Section 7.8(a) of this Agreement. 

“Early Termination Date” means the date of an Early Termination Notice for purposes of determining the Early
Termination Payment. 
 “Early Termination Effective Date” means the date on which an Early Termination Schedule
becomes binding pursuant to Section 4.2. 
 “Early Termination Notice” is defined in Section 4.2 of this
Agreement. 
 “Early Termination Schedule” is defined in Section 4.2 of this Agreement.  

“Early Termination Payment” is defined in Section 4.3(b) of this Agreement. 

“Early Termination Rate” means LIBOR plus 100 basis points. 

“Exchange” is defined in the Recitals of this Agreement. 

“Exchange Agreement” means the Exchange Agreement, dated on or about the date hereof, between the Corporate Taxpayer,
OpCo and the holders of Units from time to time party thereto, as amended from time to time. 
 “Exchange Basis
Schedule” is defined in Section 2.1 of this Agreement. 
 “Exchange Date” means the date of any
Exchange. 
 “Exchange Notice” means a notice delivered pursuant to Section 2.1(b) of the Exchange Agreement.

 “Existing Shareholder” means an equity holder of a Blocker TRA Party at the time of a Blocker TRA Party Merger.

 “Existing Shareholders Representative” means
[            ]. 
 “Expert” is defined in
Section 7.9 of this Agreement. 
 “Hypothetical Tax Liability” means, with respect to any Taxable Year, the
liability for Taxes of (i) the Corporate Taxpayer and (ii) without duplication, OpCo, but only 

  
 5 

 
with respect to Taxes imposed on OpCo and allocable to the Corporate Taxpayer, in each case using the same methods, elections, conventions and similar practices used on the relevant Corporate
Taxpayer Return, but (a) without taking into account Pre-Merger NOLs, if any, (b) using the Non-Stepped Up Tax Basis as reflected on the Exchange Basis Schedule including amendments thereto for the Taxable Year and (c) excluding any
deduction attributable to Imputed Interest in respect of an Exchange for the Taxable Year. For the avoidance of doubt, Hypothetical Tax Liability shall be determined without taking into account the carryover or carryback of any Tax item (or portions
thereof) that is attributable to a Basis Adjustment, or Pre-Merger NOLs or Imputed Interest, as applicable. 
 “Imputed
Interest” in respect of a TRA Party shall mean any interest imputed under Section 1272, 1274 or 483 or other provision of the Code and any similar provision of state and local tax law with respect to the Corporate Taxpayer’s
payment obligations in respect of such TRA Party under this Agreement. 
 “IPO” means the initial public offering of
Class A Shares by the Corporate Taxpayer. 
 “IPO Date” means the closing date of the IPO. 

“IRS” means the United States Internal Revenue Service. 

“LIBOR” means during any period, an interest rate per annum equal to the one-year LIBOR reported, on the date two days
prior to the first day of such period, on the Telerate Page 3750 (or if such screen shall cease to be publicly available, as reported on Reuters Screen page “LIBOR01” or by any other publicly available source of such market rate) for
London interbank offered rates for United States dollar deposits for such period. 
 “LP Agreement” means, with
respect to OpCo, the Fourth Amended and Restated Limited Partnership Agreement of OpCo, dated on or about the date hereof, as amended from time to time. 

“Market Value” shall mean the closing price of the Class A Shares on the applicable Exchange Date on the national
securities exchange or interdealer quotation system on which such Class A Shares are then traded or listed, as reported by the Wall Street Journal; provided, that if the closing price is not reported by the Wall Street
Journal for the applicable Exchange Date, then the Market Value shall mean the closing price of the Class A Shares on the Business Day immediately preceding such Exchange Date on the national securities exchange or interdealer quotation
system on which such Class A Shares are then traded or listed, as reported by the Wall Street Journal; provided, further, that if the Class A Shares are not then listed on a national securities exchange or interdealer
quotation system, “Market Value” shall mean the cash consideration paid for Class A Shares, or the fair market value of the other property delivered for Class A Shares, as determined by the Board in good faith. 

“Material Objection Notice” has the meaning set forth in Section 4.2 of this Agreement. 

  
 6 

 “NOL Interest Amount” has the meaning set forth in Section 3.1(c) of
this Agreement. 
 “NOL Realized Tax Benefit” means, for a Taxable Year, the excess, if any, of the Non-NOL Tax
Liability over the Hypothetical Tax Liability of (i) the Corporate Taxpayer and (ii) without duplication, OpCo, but only with respect to Taxes imposed on OpCo and allocable to the Corporate Taxpayer. If all or a portion of the actual
liability for such Taxes for the Taxable Year arises as a result of an audit by a Taxing Authority of any Taxable Year, such liability shall not be included in determining the NOL Realized Tax Benefit unless and until there has been a Determination.

 “NOL Tax Benefit” has the meaning set forth in Section 3.1(c) of this Agreement. 

“NOL Tax Benefit Payment” has the meaning set forth in Section 3.1(c) of this Agreement. 

“Non-NOL Tax Liability” means, with respect to any Taxable Year (or portion thereof) following a Blocker TRA Party
Merger, the liability for Taxes of (i) the Corporate Taxpayer and (ii) without duplication, OpCo, but only with respect to Taxes imposed on OpCo and allocable to the Corporate Taxpayer, in each case using the same methods, elections,
conventions and similar practices used on the relevant Corporate Taxpayer Return, but (a) without taking into account Pre-Merger NOLs, if any, (b) using the Non-Stepped Up Tax Basis as reflected on the Exchange Basis Schedule including
amendments thereto for the Taxable Year and (c) excluding any deduction attributable to Imputed Interest for the Taxable Year. For the avoidance of doubt, Non-NOL Tax Liability shall be determined without taking into account the carryover or
carryback of any Tax item (or portions thereof) that is attributable to a Basis Adjustment, Pre-Merger NOLs or Imputed Interest, as applicable 

“Non-Stepped Up Tax Basis” means, with respect to any Reference Asset at any time, the Tax basis that such asset would
have had at such time if no Basis Adjustments had been made. 
 “Objection Notice” has the meaning set forth in
Section 2.3(a) of this Agreement. 
 “Payment Date” means any date on which a payment is required to be made
pursuant to this Agreement. 
 “Permitted Investors” means investment funds managed by The Blackstone Group L.P. or
any of their Affiliates. 
 “Person” means any individual, corporation, firm, partnership, joint venture, limited
liability company, estate, trust, business association, organization, governmental entity or other entity. 
 “Pre-Exchange
Transfer” means any transfer (including upon the death of a Member) or distribution in respect of one or more Units (i) that occurs prior to an Exchange of such Units, and (ii) to which Section 743(b) or 734(b) of the
Code applies. 

  
 7 

 “Pre-Merger NOLs” means, without duplication, the net operating losses,
capital losses, charitable deductions, foreign tax credits and AMT credit carryforwards that the Corporate Taxpayer is entitled to utilize as a result of any Blocker TRA Party Merger that relate to periods (or portions thereof) prior to such Blocker
TRA Party Merger; provided, however, that in order to determine whether any such Tax attribute is a Pre-Merger NOL, the Taxable Year of the Corporate Taxpayer that includes the effective date of the relevant Blocker TRA Party Merger shall be deemed
to end as of the close of such effective date. Notwithstanding the foregoing, the term “Pre-Merger NOL” shall not include any Tax attribute of a Blocker TRA Party that is used to offset Taxes of the Blocker TRA Party, if such offset Taxes
are attributable to taxable periods (or portion thereof) ending on or prior to the date of the applicable Blocker TRA Party Merger. 

“Realized Tax Benefit” means, for a Taxable Year, the excess, if any, of the Hypothetical Tax Liability over the
actual liability for Taxes of (i) the Corporate Taxpayer and (ii) without duplication, OpCo, but only with respect to Taxes imposed on OpCo and allocable to the Corporate Taxpayer. If all or a portion of the actual liability for such
Taxes for the Taxable Year arises as a result of an audit by a Taxing Authority of any Taxable Year, such liability shall not be included in determining the Realized Tax Benefit unless and until there has been a Determination. 

“Realized Tax Detriment” means, for a Taxable Year, the excess, if any, of the actual liability for Taxes of
(i) the Corporate Taxpayer and (ii) without duplication, OpCo, but only with respect to Taxes imposed on OpCo and allocable to the Corporate Taxpayer, over the Hypothetical Tax Liability. If all or a portion of the actual liability for
such Taxes for the Taxable Year arises as a result of an audit by a Taxing Authority of any Taxable Year, such liability shall not be included in determining the Realized Tax Detriment unless and until there has been a Determination. 

“Reconciliation Dispute” is defined in Section 7.9 of this Agreement. 

“Reconciliation Procedures” is defined in Section 2.3(a) of this Agreement. 

“Reference Asset” means an asset that is held by OpCo, or by any of its direct or indirect Subsidiaries treated as a
partnership or disregarded entity (but only if such indirect Subsidiaries are held only through Subsidiaries treated as partnerships or disregarded entities) for purposes of the applicable Tax, at the time of an Exchange. A Reference Asset also
includes any asset that is “substituted basis property” under Section 7701(a)(42) of the Code with respect to a Reference Asset. 

“Schedule” means any of the following: (i) an Exchange Basis Schedule; (ii) a Tax Benefit Schedule; or
(iii) the Early Termination Schedule. 
 “Senior Obligations” is defined in Section 5.1 of this Agreement.

 “Subsidiaries” means, with respect to any Person, as of any date of determination, any other Person as to which
such Person, owns, directly or indirectly, or otherwise controls more than 50% of the voting power or other similar interests or the sole general partner interest or managing member or similar interest of such Person. 

  
 8 

 “Tax Benefit Payment” is defined in Section 3.1(b) of this
Agreement. 
 “Tax Benefit Schedule” is defined in Section 2.2 of this Agreement. 

“Tax Return” means any return, declaration, report or similar statement required to be filed with respect to Taxes
(including any attached schedules), including, without limitation, any information return, claim for refund, amended return and declaration of estimated Tax. 

“Taxable Year” means a taxable year of the Corporate Taxpayer as defined in Section 441(b) of the Code or
comparable section of state or local tax law, as applicable (and, therefore, for the avoidance of doubt, may include a period of less than 12 months for which a Tax Return is made), ending on or after the IPO Date. 

“Taxes” means any and all United States federal, state, local and foreign taxes, assessments or similar charges that
are based on or measured with respect to net income or profits, and any interest related to such Tax. 
 “Taxing
Authority” shall mean any domestic, federal, national, state, county or municipal or other local government, any subdivision, agency, commission or authority thereof, or any quasi-governmental body exercising any taxing authority or any
other authority exercising Tax regulatory authority. 
 “TRA Party” is defined in the Preamble to this Agreement.

 “TRA Party Representative” means, initially,
[            ], and thereafter, that TRA Party or committee of TRA Parties determined from time to time by a plurality vote of the TRA Parties ratably in accordance with their right to
receive Early Termination Payments hereunder if all TRA Parties had fully Exchanged their Units for Class A Shares or other consideration and the Corporate Taxpayer had exercised its right of early termination on the date of the most recent
Exchange. 
 “Treasury Regulations” means the final, temporary and proposed regulations under the Code promulgated
from time to time (including corresponding provisions and succeeding provisions) as in effect for the relevant taxable period. 

“Units” is defined in the Recitals of this Agreement. 

“Valuation Assumptions” shall mean, as of an Early Termination Date, the assumptions that in each Taxable Year ending
on or after such Early Termination Date, (1) the Corporate Taxpayer will have taxable income sufficient to fully utilize the deductions arising from the Basis Adjustments and the Imputed Interest during such Taxable Year or future Taxable Years
(including, for the avoidance of doubt, Basis Adjustments and Imputed Interest that would result from future Tax Benefit Payments that would be paid in accordance with the Valuation Assumptions) in which such deductions would become available,
(2) any Pre-Merger 

  
 9 

 
NOLs or loss carryovers generated by deductions arising from Basis Adjustments or Imputed Interest that are available as of the date of such Early Termination Date will be used by the Corporate
Taxpayer on a pro rata basis from the date of such Early Termination Date through the earlier of (x) the scheduled expiration date under applicable Tax law of such Pre-Merger NOLs or loss carryovers or (y) the fifth (5th) anniversary
of the Early Termination Date, (3) the United States federal, state and local income tax rates that will be in effect for each such Taxable Year will be those specified for each such Taxable Year by the Code and other law as in effect on the
Early Termination Date, (4) any non-amortizable assets will be disposed of on the fifteenth (15th) anniversary of the applicable Basis Adjustment and any cash equivalents will be disposed of twelve (12) months following the Early
Termination Date; provided, that in the event of a Change of Control, such non-amortizable assets shall be deemed disposed of at the time of sale (if applicable) of the relevant asset in the Change of Control (if earlier than such fifteenth
(15th) anniversary) and (5) if, at the Early Termination Date, there are Units that have not been Exchanged, then each such Unit shall be deemed Exchanged for the Market Value of the Class A Shares and the amount of cash that would be
transferred if the Exchange occurred on the Early Termination Date. 
 ARTICLE II 

DETERMINATION OF CERTAIN REALIZED TAX BENEFIT 

Section 2.1 Basis Adjustment. Within ninety (90) calendar days after the filing of the United States federal income
tax return of the Corporate Taxpayer for each Taxable Year in which an Exchange has been effected by any TRA Party, the Corporate Taxpayer shall deliver to such TRA Party a schedule (the “Exchange Basis Schedule”) that shows,
in reasonable detail necessary to perform the calculations required by this Agreement (i) the Non-Stepped Up Tax Basis of the Reference Assets in respect of such TRA Party as of each applicable Exchange Date, (ii) the Basis Adjustment with
respect to the Reference Assets in respect of such TRA Party as a result of the Exchanges effected in such Taxable Year by such TRA Party, calculated in the aggregate, (iii) the period (or periods) over which the Reference Assets in respect of
such TRA Party are amortizable and/or depreciable and (iv) the period (or periods) over which each Basis Adjustment in respect of such TRA Party is amortizable and/or depreciable. 

Section 2.2 Tax Benefit Schedule. 

(a) Tax Benefit Schedule. Within ninety (90) calendar days after the filing of the United States federal income tax return of the
Corporate Taxpayer for any Taxable Year in which there is a Realized Tax Benefit, an NOL Realized Tax Benefit or a Realized Tax Detriment in respect of such TRA Party (or, following a Blocker TRA Party Merger, an Existing Shareholder), the Corporate
Taxpayer shall provide to such TRA Party (or, in the case of an Existing Shareholder, the Existing Shareholders Representative) a schedule showing, in reasonable detail, the calculation of the Tax Benefit Payment or NOL Tax Benefit Payment in
respect of such TRA Party or Existing Shareholder for such Taxable Year (a “Tax Benefit Schedule”). Each Tax Benefit Schedule will become final as provided in Section 2.3(a) and may be amended as provided in
Section 2.3(b) (subject to the procedures set forth in Section 2.3(b)).

  
 10 

 (b) Applicable Principles. Subject to Section 3.3(a), the Realized Tax Benefit, NOL
Realized Tax Benefit or Realized Tax Detriment for each Taxable Year is intended to measure the decrease or increase in the actual liability for Taxes of the Corporate Taxpayer for such Taxable Year attributable to the Basis Adjustments, any
Pre-Merger NOLs and Imputed Interest, determined using a “with and without” methodology. Carryovers or carrybacks of any Pre-Merger NOLs, Tax item attributable to the Basis Adjustments and Imputed Interest shall be considered to be subject
to the rules of the Code and the Treasury Regulations or the appropriate provisions of U.S. state and local income and franchise tax law, as applicable, governing the use, limitation and expiration of carryovers or carrybacks of the relevant type.
If a carryover or carryback of any Tax item includes a portion that is attributable to any Pre-Merger NOLs, Basis Adjustments or Imputed Interest and another portion that is not, such portions shall be considered to be used in accordance with the
“with and without” methodology. The parties agree that (i) all Tax Benefit Payments attributable to the Basis Adjustments (other than Imputed Interest) will be treated as subsequent upward purchase price adjustments that have the
effect of creating additional Basis Adjustments to Reference Assets for the Corporate Taxpayer in the year of payment, (ii) as a result, such additional Basis Adjustments will be incorporated into the current year calculation and into future
year calculations, as appropriate, (iii) all NOL Tax Benefits Payments (other than Imputed Interest) will be treated as subsequent upward purchase price adjustments in the applicable Blocker TRA Party Merger and (iv) the actual liability
for Taxes will take into account the deduction of the portion of the Tax Benefit Payment or NOL Tax Benefit Payment that must be accounted for as Imputed Interest. 

Section 2.3 Procedures, Amendments. 

(a) Procedure. Every time the Corporate Taxpayer delivers to a TRA Party an applicable Schedule under this Agreement, including any
Amended Schedule delivered pursuant to Section 2.3(b), and any Early Termination Schedule or amended Early Termination Schedule, the Corporate Taxpayer shall also (x) deliver to such TRA Party supporting schedules and work papers, as
determined by the Corporate Taxpayer or as reasonably requested by such TRA Party, providing reasonable detail regarding data and calculations that were relevant for purposes of preparing the Schedule and (y) allow such TRA Party reasonable
access at no cost to the appropriate representatives at the Corporate Taxpayer, as determined by the Corporate Taxpayer or as reasonably requested by such TRA Party, in connection with a review of such Schedule. Without limiting the generality of
the preceding sentence, the Corporate Taxpayer shall ensure that any Tax Benefit Schedule that is delivered to a TRA Party, along with any supporting schedules and work papers, provides a reasonably detailed presentation of the calculation of the
actual liability of the Corporate Taxpayer for Taxes, the Hypothetical Tax Liability, and the Non-NOL Tax Liability, and identifies any material assumptions or operating procedures or principles that were used for purposes of such calculations. An
applicable Schedule or amendment thereto shall become final and binding on all parties thirty (30) calendar days from the date on which all relevant TRA Parties are treated as having received the applicable Schedule or amendment thereto under
Section 7.1 unless the TRA Party Representative (i) within thirty (30) calendar days from such date provides the Corporate Taxpayer with notice of a material objection to such Schedule (“Objection Notice”) made in
good faith or (ii) provides a written waiver of such right of any Objection Notice within the period described in clause (i) above, in which case such Schedule or amendment thereto becomes binding on the date the waiver is received by the
Corporate Taxpayer. If the Corporate Taxpayer and the TRA Party Representative, for any 

  
 11 

 
reason, are unable to successfully resolve the issues raised in the Objection Notice within thirty (30) calendar days after receipt by the Corporate Taxpayer of an Objection Notice, the
Corporate Taxpayer and the TRA Party Representative shall employ the reconciliation procedures as described in Section 7.9 of this Agreement (the “Reconciliation Procedures”). The TRA Party Representative will fairly
represent the interests of each of the TRA Parties and shall timely raise and pursue, in accordance with this Section 2.3(a), any reasonable objection to a Schedule or amendment thereto timely communicated in writing to the TRA Party
Representative by a TRA Party. 
 (b) Amended Schedule. The applicable Schedule for any Taxable Year may be amended from time to time
by the Corporate Taxpayer (i) in connection with a Determination affecting such Schedule, (ii) to correct inaccuracies in the Schedule identified as a result of the receipt of additional factual information relating to a Taxable Year after
the date the Schedule was provided to a TRA Party, (iii) to comply with the Expert’s determination under the Reconciliation Procedures, (iv) to reflect a change in the Realized Tax Benefit, NOL Realized Tax Benefit or Realized Tax
Detriment for such Taxable Year attributable to a carryback or carryforward of a loss or other tax item to such Taxable Year, (v) to reflect a change in the Realized Tax Benefit, NOL Realized Tax Benefit or Realized Tax Detriment for such
Taxable Year attributable to an amended Tax Return filed for such Taxable Year, or (vi) to adjust an applicable Exchange Basis Schedule to take into account payments made pursuant to this Agreement (any such Schedule, an “Amended
Schedule”). The Corporate Taxpayer shall provide an Amended Schedule to each TRA Party within thirty (30) calendar days of the occurrence of an event referenced in clauses (i) through (vi) of the preceding sentence. 

(c) In connection with any Blocker TRA Party Merger, in addition to the consideration otherwise received by the Existing Shareholders from the
Corporate Taxpayer as a result of such Blocker TRA Party Merger, the Corporate Taxpayer shall transfer (or shall cause to be transferred) to each Existing Shareholder, an interest under this Agreement equivalent to the Existing Shareholder’s
pro rata portion of the interest in this Agreement held by such Blocker TRA Party at the effective time of such Blocker TRA Party Merger. 

ARTICLE III 

TAX BENEFIT PAYMENTS 

Section 3.1 Payments. 

(a) Payments. Within five (5) calendar days after a Tax Benefit Schedule delivered to a TRA Party (or Existing Shareholders
Representative) becomes final in accordance with Section 2.3(a), the Corporate Taxpayer shall pay such TRA Party (or Existing Shareholder Representative, which shall pay to the applicable Existing Shareholder) for such Taxable Year (i) the
Tax Benefit Payment determined pursuant to Section 3.1(b) that is allocable to such TRA Party, and/or (ii) the NOL Tax Benefit Payment determined pursuant to Section 3.1(c) that is allocable to such Existing Shareholder. Each
such Tax Benefit Payment or NOL Tax Benefit Payment shall be made by wire transfer of immediately available funds to the bank account previously designated by such TRA Party to the Corporate Taxpayer or as otherwise agreed by the Corporate Taxpayer
and such TRA Party. For the avoidance of doubt, (x) no Tax Benefit 

  
 12 

 
Payment or NOL Tax Benefit Payment shall be made in respect of estimated tax payments, including, without limitation, federal estimated income tax payments and (y) the payments provided for
pursuant to clause (i) of the above sentence shall be computed separately for each Exchange. 
 (b) A “Tax Benefit
Payment” in respect of a TRA Party for a Taxable Year means an amount, not less than zero, equal to the sum of the portion of the Net Tax Benefit that is allocable to such TRA Party and the Interest Amount with respect thereto. For the
avoidance of doubt, for Tax purposes, the Interest Amount shall not be treated as interest but instead shall be treated as additional consideration for the acquisition of Units in Exchanges, unless otherwise required by law. Subject to
Section 3.3(a), the “Net Tax Benefit” for a Taxable Year shall be an amount equal to the excess, if any, of 85% of the Cumulative Net Realized Tax Benefit as of the end of such Taxable Year, over the total amount of
payments previously made under clause (i) of the first sentence of Section 3.1(a) (excluding payments attributable to Interest Amounts); provided, for the avoidance of doubt, that no such recipient shall be required to return any
portion of any previously made Tax Benefit Payment. The “Interest Amount” shall equal the interest on the Net Tax Benefit calculated at the Agreed Rate from the due date (without extensions) for filing the Corporate Taxpayer
Return with respect to Taxes for such Taxable Year until the payment date under Section 3.1(a). The Net Tax Benefit and the Interest Amount shall be determined separately with respect to each Exchange, on a Unit-by-Unit basis by reference to
the resulting Basis Adjustment to the Corporate Taxpayer. Notwithstanding the foregoing, for each Taxable Year ending on or after the date of a Change of Control that occurs after the IPO Date, all Tax Benefit Payments paid with respect to the Units
that were Exchanged after the effective time of such Change of Control shall be calculated by utilizing Valuation Assumptions (1), (2) and (4), substituting in each case the terms “date of a Change of Control” for an “Early
Termination Date.” 
 (c) An “NOL Tax Benefit Payment” in respect of an Existing Shareholder for a Taxable Year
after such Blocker TRA Party engages in a Blocker TRA Party Merger, means an amount, not less than zero, equal to the sum of the portion of the NOL Net Tax Benefit that is allocable to such Existing Shareholder and the NOL Interest Amount with
respect thereto. Subject to Section 3.3(a), the “NOL Net Tax Benefit” for a Taxable Year shall be an amount equal to the excess, if any, of 85% of the Cumulative NOL Net Realized Tax Benefit as of the end of such Taxable
Year, over the total amount of payments previously made under clause (ii) of the first sentence of Section 3.1(a) (excluding payments attributable to NOL Interest Amounts); provided, for the avoidance of doubt, that no such recipient shall
be required to return any portion of any previously made NOL Tax Benefit Payment. The “NOL Interest Amount” shall equal the interest on the NOL Net Tax Benefit calculated at the Agreed Rate from the due date (without
extensions) for filing the Corporate Taxpayer Return with respect to Taxes for such Taxable Year until the payment date under Section 3.1(a). Notwithstanding the foregoing, for each Taxable Year ending on or after the date of a Change of
Control that occurs after the IPO Date, all NOL Tax Benefit Payments paid with respect to a Blocker TRA Party Merger occurring after the effective time of such Change of Control, shall be calculated by utilizing Valuation Assumptions (1),
(2) and (4), substituting in each case the terms “closing date of a Change of Control” for an “Early Termination Date.” 

  
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 Section 3.2 No Duplicative Payments. It is intended that the provisions of this
Agreement will not result in duplicative payment of any amount (including interest) required under this Agreement. The provisions of this Agreement shall be construed in the appropriate manner to ensure such intentions are realized. 

Section 3.3 Pro Rata Payments. 

(a) Notwithstanding anything in Section 3.1 to the contrary, to the extent that the aggregate Tax benefit of the Corporate Taxpayer with
respect to the Pre-Merger NOLs, the Basis Adjustments or Imputed Interest, as such terms are defined in this Agreement, is limited in a particular Taxable Year because the Corporate Taxpayer does not have sufficient taxable income, the Net Tax
Benefit or the NOL Net Tax Benefit for the Corporate Taxpayer shall be allocated among all parties eligible for a Tax Benefit Payment (in the case of the Net Tax Benefit) or NOL Tax Benefit Payment (in the case of the NOL Net Tax Benefit) under this
Agreement in proportion to the amounts of Net Tax Benefit and NOL Net Tax Benefit, respectively, that would have been allocated to each party if the Corporate Taxpayer had sufficient taxable income so that there were no such limitation. 

(b) After taking into account Section 3.3(a), if for any reason the Corporate Taxpayer does not fully satisfy its payment obligations to
make all Tax Benefit Payments and NOL Tax Benefit Payments due under this Agreement in respect of a particular Taxable Year, then the Corporate Taxpayer and the TRA Parties agree that no Tax Benefit Payment or NOL Tax Benefit Payment shall be made
in respect of any Taxable Year until all Tax Benefit Payments in respect of prior Taxable Years have been made in full. 
 ARTICLE IV

 TERMINATION 

Section 4.1 Early Termination of Agreement; Breach of Agreement. 

(a) The Corporate Taxpayer may terminate this Agreement with respect to all amounts payable to the TRA Parties and with respect to all of the
Units held by the TRA Parties at any time by paying to each TRA Party the Early Termination Payment in respect of such TRA Party; provided, however, that this Agreement shall only terminate upon the receipt of the Early Termination
Payment by all TRA Parties, and provided, further, that the Corporate Taxpayer may withdraw any notice to execute its termination rights under this Section 4.1(a) prior to the time at which any Early Termination Payment has been
paid. Upon payment of the Early Termination Payment by the Corporate Taxpayer, none of the TRA Parties or the Corporate Taxpayer shall have any further payment obligations under this Agreement, other than for any (a) Tax Benefit Payment or
NOL Tax Benefit Payment due and payable and that remains unpaid as of the Early Termination Notice and (b) Tax Benefit Payment or NOL Tax Benefit Payment due for the Taxable Year ending with or including the date of the Early Termination Notice
(except to the extent that the amount described in clause (b) is included in the Early Termination Payment). If an Exchange or Blocker TRA Party Merger occurs after the Corporate Taxpayer makes all of the required Early Termination
Payments, the Corporate Taxpayer shall have no obligations under this Agreement with respect to such Exchange or Blocker TRA Party Merger, as the case may be. 

  
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 (b) In the event that the Corporate Taxpayer (1) breaches any of its material obligations
under this Agreement, whether as a result of failure to make any payment when due, failure to honor any other material obligation required hereunder or by operation of law as a result of the rejection of this Agreement in a case commenced under the
Bankruptcy Code or otherwise or (2) (A) shall commence any case, proceeding or other action (i) under any existing or future law of any jurisdiction, domestic or foreign, relating to bankruptcy, insolvency, reorganization or relief of
debtors, seeking to have an order for relief entered with respect to it, or seeking to adjudicate it a bankrupt or insolvent, or seeking reorganization, arrangement, adjustment, winding-up, liquidation, dissolution, composition or other relief with
respect to it or its debts or (ii) seeking an appointment of a receiver, trustee, custodian, conservator or other similar official for it or for all or any substantial part of its assets, or it shall make a general assignment for the benefit of
creditors or (B) there shall be commenced against Corporate Taxpayer any case, proceeding or other action of the nature referred to in clause (A) above that remains undismissed or undischarged for a period of 60 days, all obligations
hereunder shall be automatically accelerated and shall be immediately due and payable, and such obligations shall be calculated as if an Early Termination Notice had been delivered on the date of such breach and shall include, but not be limited to,
(1) the Early Termination Payments calculated as if an Early Termination Notice had been delivered on the date of a breach, (2) any Tax Benefit Payment or NOL Tax Benefit Payment due and payable and that remains unpaid as of the date of a
breach, and (3) any Tax Benefit Payment or NOL Tax Benefit Payment in respect of any TRA Party due for the Taxable Year ending with or including the date of a breach; provided that procedures similar to the procedures of Section 4.2 shall
apply with respect to the determination of the amount payable by the Corporate Taxpayer pursuant to this sentence. Notwithstanding the foregoing (other than as set forth in subsection (2) above), in the event that the Corporate Taxpayer
breaches this Agreement, each TRA Party shall be entitled to elect to receive the amounts set forth in clauses (1), (2) and (3) above or to seek specific performance of the terms hereof. The parties agree that the failure to make any
payment due pursuant to this Agreement within three months of the date such payment is due shall be deemed to be a breach of a material obligation under this Agreement for all purposes of this Agreement, and that it will not be considered to be a
breach of a material obligation under this Agreement to make a payment due pursuant to this Agreement within three months of the date such payment is due. Notwithstanding anything in this Agreement to the contrary, it shall not be a breach of this
Agreement if the Corporate Taxpayer fails to make any Tax Benefit Payment when due to the extent that the Corporate Taxpayer has insufficient funds to make such payment in the Corporate Taxpayer’s sole judgment exercised in good faith;
provided that the interest provisions of Section 5.2 shall apply to such late payment (unless the Corporate Taxpayer does not have sufficient cash to make such payment as a result of limitations imposed by existing credit agreements to
which OpCo or any its Subsidiaries is a party, in which case Section 5.2 shall apply, but the Default Rate shall be replaced by the Agreed Rate). 

(c) In the event of a Change of Control, then all obligations hereunder with respect to any Exchanges or Pre-Merger NOLs from any Blocker TRA
Party Merger occurring prior to such Change of Control shall be accelerated and such obligations shall be calculated as if an Early Termination Notice had been delivered on the date of such Change of Control and shall

  
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include (1) the Early Termination Payments calculated with respect to such prior Exchanges or Pre-Merger NOLs as if the Early Termination Date is the date of such Change of Control,
(2) any Tax Benefit Payment or NOL Tax Benefit Payment due and payable and that remains unpaid as of the date of such Change of Control, and (3) any Tax Benefit Payment or NOL Tax Benefit Payment in respect of any TRA Party due for the
Taxable Year ending with or including the date of such Change of Control. In the event of a Change of Control, any Early Termination Payment described in the preceding sentence shall be calculated utilizing Valuation Assumptions (1), (2),
(3) and (4), substituting in each case the terms “date of a Change of Control” for an “Early Termination Date.” Any Exchanges or Pre-Merger NOLs with respect to which a payment has been made under this Section 4.1(c)
shall be excluded in calculating any future Tax Benefit Payments, NOL Tax Benefit Payments or Early Termination Payments, and this Agreement shall have no further application to such Exchanges or Pre-Merger NOLs. 

Section 4.2 Early Termination Notice. If the Corporate Taxpayer chooses to exercise its right of early termination under
Section 4.1 above, the Corporate Taxpayer shall deliver to each TRA Party notice of such intention to exercise such right (“Early Termination Notice”) and a schedule (the “Early Termination
Schedule”) specifying the Corporate Taxpayer’s intention to exercise such right and showing in reasonable detail the calculation of the Early Termination Payment(s) due for each TRA Party. Each Early Termination Schedule shall
become final and binding on all parties thirty (30) calendar days from the first date on which all TRA Parties are treated as having received such Schedule or amendment thereto under Section 7.1 unless the TRA Party Representative
(i) within thirty (30) calendar days after such date provides the Corporate Taxpayer with notice of a material objection to such Schedule made in good faith (“Material Objection Notice”) or (ii) provides a
written waiver of such right of a Material Objection Notice within the period described in clause (i) above, in which case such Schedule becomes binding on the date the waiver is received by the Corporate Taxpayer. If the Corporate Taxpayer and
the TRA Party Representative, for any reason, are unable to successfully resolve the issues raised in such notice within thirty (30) calendar days after receipt by the Corporate Taxpayer of the Material Objection Notice, the Corporate Taxpayer
and the TRA Party Representative shall employ the Reconciliation Procedures in which case such Schedule becomes binding ten (10) days after the conclusion of the Reconciliation Procedures. The TRA Party Representative will fairly represent the
interests of each of the TRA Parties and shall timely raise and pursue, in accordance with this Section 4.2, any reasonable objection to an Early Termination Schedule or amendment thereto timely communicated in writing to the TRA Party
Representative by a TRA Party. 
 Section 4.3 Payment upon Early Termination. 

(a) Within three (3) calendar days after an Early Termination Effective Date, the Corporate Taxpayer shall pay to the TRA Party an amount
equal to the Early Termination Payment in respect of such TRA Party. Such payment shall be made by wire transfer of immediately available funds to a bank account or accounts designated by the TRA Party or as otherwise agreed by the Corporate
Taxpayer and such TRA Party. 
 (b) “Early Termination Payment” in respect of a TRA Party shall equal the present
value, discounted at the Early Termination Rate as of the applicable Early Termination Effective Date, of all Tax Benefit Payments or NOL Tax Benefit Payments in respect of such 

  
 16 

 
TRA Party that would be required to be paid by the Corporate Taxpayer beginning from the Early Termination Date and assuming that the Valuation Assumptions in respect of such TRA Party are
applied. 
 ARTICLE V 

SUBORDINATION AND LATE PAYMENTS 

Section 5.1 Subordination. Notwithstanding any other provision of this Agreement to the contrary, any Tax Benefit Payment or
Early Termination Payment required to be made by the Corporate Taxpayer to the TRA Parties under this Agreement shall rank subordinate and junior in right of payment to any principal, interest or other amounts due and payable in respect of any
obligations in respect of indebtedness for borrowed money of the Corporate Taxpayer and its Subsidiaries (“Senior Obligations”) and shall rank pari passu in right of payment with all current or future unsecured
obligations of the Corporate Taxpayer that are not Senior Obligations. To the extent that any payment under this Agreement is not permitted to be made at the time payment is due as a result of this Section 5.1 and the terms of agreements
governing Senior Obligations, such payment obligation nevertheless shall accrue for the benefit of TRA Parties and the Corporate Taxpayer shall make such payments at the first opportunity that such payments are permitted to be made in accordance
with the terms of the Senior Obligations.  
 Section 5.2 Late Payments by the Corporate Taxpayer. The amount of all or
any portion of any Tax Benefit Payment, NOL Tax Benefit Payment or Early Termination Payment not made to the TRA Parties when due under the terms of this Agreement, whether as a result of Section 5.1 or otherwise, shall be payable together with
any interest thereon, computed at the Default Rate and commencing from the date on which such Tax Benefit Payment, NOL Tax Benefit Payment or Early Termination Payment was first due and payable to the date of actual payment. 

ARTICLE VI 
 NO
DISPUTES; CONSISTENCY; COOPERATION 
 Section 6.1 Participation in the Corporate Taxpayer’s and OpCo’s Tax
Matters. Except as otherwise provided herein, and except as provided in Article V of the LP Agreement, the Corporate Taxpayer shall have full responsibility for, and sole discretion over, all Tax matters concerning the Corporate Taxpayer and
OpCo, including without limitation the preparation, filing or amending of any Tax Return and defending, contesting or settling any issue pertaining to Taxes. Notwithstanding the foregoing, the Corporate Taxpayer shall notify the TRA Party
Representative of, and keep the TRA Party Representative reasonably informed with respect to, the portion of any audit of the Corporate Taxpayer and OpCo by a Taxing Authority the outcome of which is reasonably expected to materially affect the
rights and obligations of a TRA Party under this Agreement, and shall provide to the TRA Party Representative reasonable opportunity to provide information and other input to the Corporate Taxpayer, OpCo and their respective advisors concerning the
conduct of any such portion of such audit; provided, however, that the Corporate Taxpayer and OpCo shall not be required to take any action that is inconsistent with any provision of the LP Agreement. 

  
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 Section 6.2 Consistency. The Corporate Taxpayer and the TRA Parties agree to
report and cause to be reported for all purposes, including federal, state and local Tax purposes and financial reporting purposes, all Tax-related items (including, without limitation, the Basis Adjustments and each Tax Benefit Payment or NOL Tax
Benefit Payment) in a manner consistent with that contemplated by this Agreement or specified by the Corporate Taxpayer in any Schedule required to be provided by or on behalf of the Corporate Taxpayer under this Agreement unless otherwise required
by law. The Corporate Taxpayer shall (and shall cause OpCo and its other Subsidiaries to) use reasonable efforts (for the avoidance of doubt, taking into account the interests and entitlements of all TRA Parties under this Agreement) to defend the
Tax treatment contemplated by this Agreement and any Schedule in any audit, contest or similar proceeding with any Taxing Authority. 

Section 6.3 Cooperation. Each of the TRA Parties shall (a) furnish to the Corporate Taxpayer in a timely manner such
information, documents and other materials as the Corporate Taxpayer may reasonably request for purposes of making any determination or computation necessary or appropriate under this Agreement, preparing any Tax Return or contesting or defending
any audit, examination or controversy with any Taxing Authority, (b) make itself available to the Corporate Taxpayer and its representatives to provide explanations of documents and materials and such other information as the Corporate Taxpayer
or its representatives may reasonably request in connection with any of the matters described in clause (a) above, and (c) reasonably cooperate in connection with any such matter, and the Corporate Taxpayer shall reimburse each such TRA
Party for any reasonable and documented out-of-pocket costs and expenses incurred pursuant to this Section. 
 ARTICLE VII 

MISCELLANEOUS 

Section 7.1 Notices. All notices, requests, claims, demands and other communications hereunder shall be in writing and
shall be deemed duly given and received (a) on the date of delivery if delivered personally, or by facsimile or email with confirmation of transmission by the transmitting equipment or (b) on the first Business Day following the date of
dispatch if delivered by a recognized next-day courier service. All notices hereunder shall be delivered as set forth below, or pursuant to such other instructions as may be designated in writing by the party to receive such notice:

If to the Corporate Taxpayer, to:

Summit Materials, Inc. 
 1550
Wynkoop Street, 3rd Floor 
 Denver, Colorado 80202 

Attention: Chief Legal Officer 

Fax: (303) 893-6993 

Email: [Anne.Benedict@Summit-Materials.com] 

  
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 with a copy to: 

Summit Materials, Inc. 
 1550
Wynkoop Street, 3rd Floor 
 Denver, Colorado 80202 

Attention: [Chief Financial Officer] 

Fax: [            ] 

Email: [Brian.Harris@summit-materials.com] 

If to the TRA Parties, to the respective addresses, fax numbers and email addresses set forth in the records of OpCo. 

Any party may change its address, fax number or email by giving the other party written notice of its new address, fax number or email in the manner set forth
above. 
 Section 7.2 Counterparts. This Agreement may be executed in one or more counterparts, all of which shall be
considered one and the same agreement and shall become effective when one or more counterparts have been signed by each of the parties and delivered to the other parties, it being understood that all parties need not sign the same counterpart.
Delivery of an executed signature page to this Agreement by facsimile transmission shall be as effective as delivery of a manually signed counterpart of this Agreement. 

Section 7.3 Entire Agreement; No Third Party Beneficiaries. This Agreement constitutes the entire agreement and supersedes all
prior agreements and understandings, both written and oral, among the parties with respect to the subject matter hereof. This Agreement shall be binding upon and inure solely to the benefit of each party hereto and their respective successors and
permitted assigns, and nothing in this Agreement, express or implied, is intended to or shall confer upon any other Person any right, benefit or remedy of any nature whatsoever under or by reason of this Agreement. 

Section 7.4 Governing Law. This Agreement shall be governed by, and construed in accordance with, the law of the State of New
York. 
 Section 7.5 Severability. If any term or other provision of this Agreement is invalid, illegal or incapable of being
enforced by any law or public policy, all other terms and provisions of this Agreement shall nevertheless remain in full force and effect so long as the economic or legal substance of the transactions contemplated hereby is not affected in any
manner materially adverse to any party. Upon such determination that any term or other provision is invalid, illegal or incapable of being enforced, the parties hereto shall negotiate in good faith to modify this Agreement so as to effect the
original intent of the parties as closely as possible in an acceptable manner in order that the transactions contemplated hereby are consummated as originally contemplated to the greatest extent possible. 

Section 7.6 Successors; Assignment; Amendments; Waivers. 

(a) Each TRA Party may assign any of its rights under this Agreement to any Person as long as such transferee has executed and delivered, or,
in connection with such 

  
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transfer, executes and delivers, a joinder to this Agreement, in form and substance reasonably satisfactory to the Corporate Taxpayer, agreeing to become a TRA Party for all purposes of this
Agreement, except as otherwise provided in such joinder. 
 (b) No provision of this Agreement may be amended unless such amendment is
approved in writing by each of the Corporate Taxpayer and by the TRA Parties who would be entitled to receive at least two-thirds of the total amount of the Early Termination Payments payable to all TRA Parties hereunder if the Corporate Taxpayer
had exercised its right of early termination on the date of the most recent Exchange prior to such amendment (excluding, for purposes of this sentence, all payments made to any TRA Party pursuant to this Agreement since the date of such most recent
Exchange); provided, that no such amendment shall be effective if such amendment will have a disproportionate effect on the payments one or more TRA Parties receive under this Agreement unless such amendment is consented in writing by such
TRA Parties disproportionately affected who would be entitled to receive at least two-thirds of the total amount of the Early Termination Payments payable to all TRA Parties disproportionately affected hereunder if the Corporate Taxpayer had
exercised its right of early termination on the date of the most recent Exchange prior to such amendment (excluding, for purposes of this sentence, all payments made to any TRA Party pursuant to this Agreement since the date of such most recent
Exchange). No provision of this Agreement may be waived unless such waiver is in writing and signed by the party against whom the waiver is to be effective. 

(c) All of the terms and provisions of this Agreement shall be binding upon, shall inure to the benefit of and shall be enforceable by the
parties hereto and their respective successors, assigns, heirs, executors, administrators and legal representatives. The Corporate Taxpayer shall require and cause any direct or indirect successor (whether by purchase, merger, consolidation or
otherwise) to all or substantially all of the business or assets of the Corporate Taxpayer, by written agreement, expressly to assume and agree to perform this Agreement in the same manner and to the same extent that the Corporate Taxpayer would be
required to perform if no such succession had taken place. 
 Section 7.7 Titles and Subtitles. The titles of the sections and
subsections of this Agreement are for convenience of reference only and are not to be considered in construing this Agreement. 
 Section
7.8 Resolution of Disputes. 
 (a) Any and all disputes which are not governed by Section 7.9 and cannot be settled amicably,
including any ancillary claims of any party, arising out of, relating to or in connection with the validity, negotiation, execution, interpretation, performance or non-performance of this Agreement (including the validity, scope and enforceability
of this arbitration provision) (each a “Dispute”) shall be finally settled by arbitration conducted by a single arbitrator in New York in accordance with the then-existing Rules of Arbitration of the International Chamber of
Commerce. If the parties to the Dispute fail to agree on the selection of an arbitrator within thirty (30) calendar days of the receipt of the request for arbitration, the International Chamber of Commerce shall make the appointment. The
arbitrator shall be a lawyer admitted to the practice of law in the State of New York and shall conduct the proceedings in the English language. Performance under this Agreement shall continue if reasonably possible during any arbitration
proceedings.

  
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 (b) Notwithstanding the provisions of paragraph (a), the Corporate Taxpayer may bring an action
or special proceeding in any court of competent jurisdiction for the purpose of compelling a party to arbitrate, seeking temporary or preliminary relief in aid of an arbitration hereunder, and/or enforcing an arbitration award and, for the purposes
of this paragraph (b), each TRA Party (i) expressly consents to the application of paragraph (c) of this Section 7.8 to any such action or proceeding, (ii) agrees that proof shall not be required that monetary damages for breach
of the provisions of this Agreement would be difficult to calculate and that remedies at law would be inadequate, and (iii) irrevocably appoints the Corporate Taxpayer as agent of such TRA Party for service of process in connection with any
such action or proceeding and agrees that service of process upon such agent, who shall promptly advise the TRA Party of any such service of process, shall be deemed in every respect effective service of process upon the TRA Party in any such action
or proceeding. 
 (c) (i) EACH PARTY HEREBY IRREVOCABLY SUBMITS TO THE JURISDICTION OF COURTS LOCATED IN NEW YORK, NEW YORK FOR THE
PURPOSE OF ANY JUDICIAL PROCEEDING BROUGHT IN ACCORDANCE WITH THE PROVISIONS OF THIS SECTION 7.8, OR ANY JUDICIAL PROCEEDING ANCILLARY TO AN ARBITRATION OR CONTEMPLATED ARBITRATION ARISING OUT OF OR RELATING TO OR CONCERNING THIS AGREEMENT. Such
ancillary judicial proceedings include any suit, action or proceeding to compel arbitration, to obtain temporary or preliminary judicial relief in aid of arbitration, or to confirm an arbitration award. The parties acknowledge that the fora
designated by this paragraph (c) have a reasonable relation to this Agreement, and to the parties’ relationship with one another; and

(ii) The parties hereby waive, to the fullest extent permitted by applicable law, any objection which they now or hereafter may have to
personal jurisdiction or to the laying of venue of any such ancillary suit, action or proceeding brought in any court referred to in the preceding paragraph of this Section 7.8 and such parties agree not to plead or claim the same. 

Section 7.9 Reconciliation. In the event that the Corporate Taxpayer and the TRA Party Representative are unable to resolve a
disagreement with respect to the matters governed by Sections 2.3 and 4.2 within the relevant period designated in this Agreement (“Reconciliation Dispute”), the Reconciliation Dispute shall be submitted for determination to
a nationally recognized expert (the “Expert”) in the particular area of disagreement mutually acceptable to both parties. The Expert shall be a partner or principal in a nationally recognized accounting or law firm, and
unless the Corporate Taxpayer and the TRA Party Representative agree otherwise, the Expert shall not, and the firm that employs the Expert shall not, have any material relationship with the Corporate Taxpayer or the TRA Party Representative or other
actual or potential conflict of interest. If the Corporate Taxpayer and the TRA Party Representative are unable to agree on an Expert within fifteen (15) calendar days of receipt by the respondent(s) of written notice of a Reconciliation
Dispute, the Expert shall be appointed by the International Chamber of Commerce Centre for Expertise. The Expert shall resolve any matter relating to the Exchange Basis Schedule or an amendment thereto or the Early Termination Schedule or an
amendment thereto within thirty (30) calendar days and shall resolve 

  
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any matter relating to a Tax Benefit Schedule or an amendment thereto within fifteen (15) calendar days or as soon thereafter as is reasonably practicable, in each case after the matter has
been submitted to the Expert for resolution. Notwithstanding the preceding sentence, if the matter is not resolved before any payment that is the subject of a disagreement would be due (in the absence of such disagreement) or any Tax Return
reflecting the subject of a disagreement is due, the undisputed amount shall be paid on the date prescribed by this Agreement and such Tax Return may be filed as prepared by the Corporate Taxpayer, subject to adjustment or amendment upon
resolution. The costs and expenses relating to the engagement of such Expert or amending any Tax Return shall be borne by the Corporate Taxpayer except as provided in the next sentence. The Corporate Taxpayer and the TRA Party
Representative shall bear their own costs and expenses of such proceeding, unless (i) the Expert adopts the TRA Party Representative’s position, in which case the Corporate Taxpayer shall reimburse the TRA Party Representative for any
reasonable out-of-pocket costs and expenses in such proceeding, or (ii) the Expert adopts the Corporate Taxpayer’s position, in which case the TRA Party Representative shall reimburse the Corporate Taxpayer for any reasonable out-of-pocket
costs and expenses in such proceeding. Any dispute as to whether a dispute is a Reconciliation Dispute within the meaning of this Section 7.9 shall be decided by the Expert. The Expert shall finally determine any Reconciliation
Dispute and the determinations of the Expert pursuant to this Section 7.9 shall be binding on the Corporate Taxpayer and each of the TRA Parties and may be entered and enforced in any court having jurisdiction.

Section 7.10 Withholding. The Corporate Taxpayer shall be entitled to deduct and withhold from any payment payable pursuant to
this Agreement such amounts as the Corporate Taxpayer is required to deduct and withhold with respect to the making of such payment under the Code or any provision of state, local or foreign tax law. To the extent that amounts are so withheld and
paid over to the appropriate Taxing Authority by the Corporate Taxpayer, such withheld amounts shall be treated for all purposes of this Agreement as having been paid to the Person in respect of whom such withholding was made. 

Section 7.11 Admission of the Corporate Taxpayer into a Consolidated Group; Transfers of Corporate Assets. 

(a) If the Corporate Taxpayer is or becomes a member of an affiliated or consolidated group of corporations that files a consolidated income
tax return pursuant to Sections 1501 et seq. of the Code or any corresponding provisions of state or local law, then: (i) the provisions of this Agreement shall be applied with respect to the group as a whole; and (ii) Tax Benefit
Payments, NOL Tax Benefit Payments, Early Termination Payments and other applicable items hereunder shall be computed with reference to the consolidated taxable income of the group as a whole. 

(b) If any entity that is obligated to make a Tax Benefit Payment or Early Termination Payment hereunder transfers one or more assets to a
corporation (or a Person classified as a corporation for United States federal income tax purposes) with which such entity does not file a consolidated tax return pursuant to Section 1501 of the Code or any corresponding provisions of state,
local or foreign law (including as a result of any series of transactions or acts), such entity, for purposes of calculating the amount of any Tax Benefit Payment or Early Termination Payment (e.g., calculating the gross income of the entity and
determining the 

  
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Realized Tax Benefit of such entity) due hereunder, shall be treated as having disposed of such asset in a fully taxable transaction on the date of such contribution. The consideration
deemed to be received by such entity shall be equal to the gross fair market value of the contributed asset. For purposes of this Section 7.11, a transfer of a partnership interest shall be treated as a transfer of the transferring
partner’s share of each of the assets and liabilities of that partnership. 
 Section 7.12 Confidentiality. 

(a) Each TRA Party and each of their assignees acknowledge and agree that the information of the Corporate Taxpayer is confidential and, except
in the course of performing any duties as necessary for the Corporate Taxpayer and its Affiliates, as required by law or legal process or to enforce the terms of this Agreement, such person shall keep and retain in the strictest confidence and not
disclose to any Person any confidential matters, acquired pursuant to this Agreement, of the Corporate Taxpayer and its Affiliates and successors, concerning OpCo and its Affiliates and successors or the Members, learned by the TRA Party heretofore
or hereafter. This Section 7.12 shall not apply to (i) any information that has been made publicly available by the Corporate Taxpayer or any of its Affiliates, becomes public knowledge (except as a result of an act of the TRA Party
in violation of this Agreement) or is generally known to the business community and (ii) the disclosure of information to the extent necessary for the TRA Party to prepare and file its Tax Returns, to respond to any inquiries regarding the same
from any taxing authority or to prosecute or defend any action, proceeding or audit by any taxing authority with respect to such returns. Notwithstanding anything to the contrary herein, each TRA Party and each of their assignees (and each
employee, representative or other agent of the TRA Party or its assignees, as applicable) may disclose to any and all Persons, without limitation of any kind, the tax treatment and tax structure of the Corporate Taxpayer, OpCo and their Affiliates,
and any of their transactions, and all materials of any kind (including opinions or other tax analyses) that are provided to the TRA Party relating to such tax treatment and tax structure. 

(b) If a TRA Party or an assignee commits a breach, or threatens to commit a breach, of any of the provisions of this Section 7.12, the
Corporate Taxpayer shall have the right and remedy to have the provisions of this Section 7.12 specifically enforced by injunctive relief or otherwise by any court of competent jurisdiction without the need to post any bond or other
security, it being acknowledged and agreed that any such breach or threatened breach shall cause irreparable injury to the Corporate Taxpayer or any of its Subsidiaries or the TRA Parties and the accounts and funds managed by the Corporate Taxpayer
and that money damages alone shall not provide an adequate remedy to such Persons. Such rights and remedies shall be in addition to, and not in lieu of, any other rights and remedies available at law or in equity. 

Section 7.13 Change in Law. Notwithstanding anything herein to the contrary, if, in connection with an actual or proposed change
in law, a TRA Party reasonably believes that the existence of this Agreement could cause income (other than income arising from receipt of a payment under this Agreement) recognized by the TRA Party upon any Exchange by such TRA Party to be treated
as ordinary income rather than capital gain (or otherwise taxed at ordinary income rates) for United States federal income tax purposes or would have other material adverse tax consequences to such TRA Party, then at the election of such TRA Party
and to the extent specified by such TRA Party, this Agreement (i) shall cease to have further effect with respect to such TRA Party, (ii) shall not apply to an Exchange by such TRA Party occurring after 

  
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a date specified by such TRA Party, or (iii) shall otherwise be amended in a manner determined by such TRA Party, provided that such amendment shall not result in an increase in payments
under this Agreement at any time as compared to the amounts and times of payments that would have been due in the absence of such amendment. 

[The remainder of this page is intentionally blank] 

  
 24 

 IN WITNESS WHEREOF, the Corporate Taxpayer and each TRA Party have duly executed this Agreement
as of the date first written above. 
  

			
	Corporate Taxpayer:
	
	SUMMIT MATERIALS, INC.
		
	By:	 	  

	Name:	 	
	Title:	 	

  

			
	TRA Parties:	 	
		
	[            ]	 	

 [Signature Page – Tax Receivable Agreement]

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