EXECUTION  COPY

                                    GUARANTEE


          GUARANTEE,  dated  as  of  January  3, 2000, made by Keystone, Inc., a
Texas  close  corporation  (the  "Guarantor"),  in favor of Chase Bank of Texas,
National  Association,  as  administrative  agent  (in  such  capacity,  the
"Administrative  Agent")  for  the  banks and financial institutions or entities
(the  "Lenders")  parties to the Credit Agreement, dated as of January 28, 1998,
as  amended,  supplemented  or otherwise modified from time to time (the "Credit
Agreement")  among  Reliant Building Products, Inc., a Delaware corporation (the
"Borrower"),  the  Lenders,  Chase  Securities,  Inc.,  as advisor and arranger,
Canadian Imperial Bank of Commerce, New York Agency, as documentation agent, and
the  Administrative  Agent.  Terms defined or referenced in the Credit Agreement
and  not  otherwise  defined  or  referenced  herein  are used herein as therein
defined  or  referenced.


                              W I T N E S S E T H:


          WHEREAS,  the  Borrower  and  the  Lenders  are  parties to the Credit
Agreement;

          WHEREAS,  the  Borrower  intends  to  complete  a restructuring of its
capital  structure  (the  "Restructuring")  to  be  implemented  through certain
amendments  to  the Credit Agreement, an exchange offer and consent solicitation
for  its  outstanding  Senior  Subordinated  Notes,  and an equity investment by
certain  entities;

          WHEREAS,  in order to effect the Restructuring, the Borrower requested
that  the  Lenders execute and deliver a consent (the "Consent") to an amendment
(the  "Third  Amendment")  of  the  Credit  Agreement  and related documentation
permitting  the  Borrower to borrow from time to time during the period from the
date  hereof  to March 31, 2000 up to $2,000,000 in the aggregate or such larger
amount  as may be acceptable to the Administrative Agent (any such borrowing, an
"Over  Advance")  in  excess  of  the  Total  Revolving  Extensions  of  Credit
outstanding  as  of  the  date  hereof;  and

          WHEREAS,  the  Lenders  have  provided the Consent which requires that
each  Over  Advance  be  guaranteed  by  the  Guarantor, which holds an indirect
interest  in  the  Borrower.

          NOW,  THEREFORE,  in  consideration of the premises and other good and
valuable  consideration,  the  receipt  and  sufficiency  of  which  are  hereby
expressly  acknowledged,  the  Guarantor  hereby  agrees with the Administrative
Agent,  for  the  ratable  benefit  of  the  Lenders,  as  follows:

          .        Guarantee.    ()     The Guarantor hereby unconditionally and
irrevocably  guarantees  to the Administrative Agent, for the ratable benefit of
the Lenders and their respective successors, indorsees, transferees and assigns,
the  prompt  and  complete  payment  and  performance  by  the Borrower when due
(whether  at  the  stated maturity, by acceleration or otherwise) of all amounts
(the  "Guaranteed  Amounts")  owing from time to time under the Credit Agreement
and  the  Notes  solely  in  respect  of  any  and  all Over Advances (including
principal  thereof  and  interest thereon, including interest accruing after the
maturity  of  the  Over  Advances  and  after  the  filing  of  any  petition in
bankruptcy,  or  the  commencement  of  any  insolvency,  reorganization or like
proceeding,  relating to the Borrower, whether or not a claim for post-filing or
post-petition  interest is allowed therein), provided that in no event shall the
Guaranteed  Amounts  exceed  the  value of the collateral on deposit in the Cash
Collateral  Account  maintained  under the Cash Collateral Agreement dated as of
the  date  hereof  (as  amended, supplemented or otherwise modified from time to
time,  the  "Cash  Collateral  Agreement")  by  the  Guarantor  in  favor of the
Administrative Agent.  At the option of the Administrative Agent, the Guaranteed
Amounts  may  be  declared  due  for  all  purposes  hereof at any time upon the
occurrence  and  during  the  continuance  of  an  Event  of  Default.

          ()          The  Guarantor  further agrees to pay any and all expenses
(including,  without  limitation,  all  reasonable  fees  and  disbursements  of
counsel)  which  may  be  paid  or  incurred  by the Administrative Agent or the
Lenders  in  enforcing, or obtaining advice of counsel in respect of, any rights
with  respect  to,  or  collecting  against, the Guarantor under this Guarantee.
Except  as  otherwise  provided  in Section 1(d), this Guarantee shall remain in
full  force  and  effect until all Obligations are paid in full, notwithstanding
that  from  time  to  time  prior  thereto  the  Borrower  may  be free from any
Obligations.

          (c)      The Guarantor agrees that whenever, at any time, or from time
to  time, it shall make any payment to the Administrative Agent, for the benefit
of  the  Lenders,  on  account  of  its  liability hereunder, it will notify the
Administrative  Agent  in writing that such payment is made under this Guarantee
for  such  purpose.

          (d)          Anything  herein  to  the  contrary notwithstanding, this
Guarantee  shall  be released automatically in its entirety, without any further
action,  and  the  Guarantor shall have no further obligation hereunder upon the
successful  completion of the Restructuring, as determined by the Administrative
Agent,  provided that the Total Revolving Extensions of Credit are then equal to
or  less  than the Borrowing Base, and provided further that there is no Default
or  Event  of  Default  in  existence  at  such  time.

          (e)       Any determination made by the Administrative Agent as to the
Guaranteed  Amounts shall, if made in good faith, be conclusive for all purposes
hereof, absent manifest error.   Once made, the Over Advances shall be deemed to
remain  outstanding  to the extent that this Guarantee has not been satisfied or
released  as provided in Section 1(c) or 1(d) and the Total Revolving Extensions
of  Credit  equal  or  exceed  the  Over  Advances.
          .     No Subrogation.  Notwithstanding any payment or payments made by
the Guarantor hereunder, or any set-off or application of funds of the Guarantor
by   the Administrative Agent or any Lender, the Guarantor shall not be entitled
to  be subrogated to any of the rights of the Administrative Agent or any Lender
against the Borrower or against any collateral security or guarantee or right of
offset  held  by  the  Administrative Agent or any Lender for the payment of the
Obligations,  nor  shall  the  Guarantor  seek  or  be  entitled  to  seek  any
contribution  or  reimbursement from the Borrower in respect of payments made by
the Guarantor hereunder, until all amounts owing to the Administrative Agent and
each  Lender by the Borrower on account of the Obligations are paid in full.  If
any  amount shall be paid to the Guarantor on account of such subrogation rights
at  any  time when all of the Obligations shall not have been paid in full, such
amount  shall be held by the Guarantor in trust for the Administrative Agent and
the  Lenders, segregated from other funds of the Guarantor, and shall, forthwith
upon receipt by the Guarantor, be turned over to the Administrative Agent in the
exact  form  received  by  the  Guarantor (duly indorsed by the Guarantor to the
Administrative  Agent,  if  required),  to  be  applied against the Obligations,
whether  matured  or  unmatured,  in  such order as the Administrative Agent may
determine.

          .          Amendments, etc. with respect to the Obligations; Waiver of
Rights.    The  Guarantor shall remain obligated hereunder notwithstanding that,
without  any  reservation of rights against the Guarantor, and without notice to
or  further  assent  by  the  Guarantor,  any  demand  for payment of any of the
Guaranteed  Amounts  made  by  the  Administrative  Agent  or  any Lender may be
rescinded,  and  any  of  the  Guaranteed  Amounts continued, and the Guaranteed
Amounts,  or  the  liability of any other party upon or for any part thereof, or
any  collateral  security  or guarantee therefor or right of offset with respect
thereto,  may,  from  time  to  time, in whole or in part, be renewed, extended,
amended,  modified, accelerated, compromised, waived, surrendered or released by
the  Lenders,  and  any collateral security, guarantee or right of offset at any
time  held by the Lenders for the payment of the Guaranteed Amounts may be sold,
exchanged, waived, surrendered or released.  The Lenders  and the Administrative
Agent  shall  not  have any obligation to protect, secure, perfect or insure any
lien  at  any  time  held  by  it  as  security  for the Obligations or for this
Guarantee  or any property subject thereto or to liquidate the collateral in any
manner,  commencing  on  any  date  or over any period other than as required by
applicable  law.    When  making any demand hereunder against the Guarantor, the
Administrative  Agent  or  each Lender may, but shall be under no obligation to,
make a similar demand on the Borrower or any other guarantor, and any failure to
make  any  such  demand or to collect any payments from the Borrower or any such
other guarantor or any release of the Borrower or such other guarantor shall not
relieve the Guarantor of its obligations or liabilities hereunder, and shall not
impair  or affect the rights and remedies, express or implied, or as a matter of
law,  of  any  Lender  against  the Guarantor.  For the purposes hereof "demand"
shall  include  the  commencement  and  continuance  of  any  legal proceedings.

          .      Guarantee Absolute and Unconditional.  The Guarantor waives any
and  all notice of the creation, renewal, extension or accrual of any Guaranteed
Amounts  and  notice of or proof of reliance by the Administrative Agent and the
Lenders  upon  this  Guarantee  or  acceptance of this Guarantee; the Guaranteed
Amounts,  and  any  of  them, shall conclusively be deemed to have been created,
contracted  or  incurred,  or  renewed, extended, amended or waived, in reliance
upon this Guarantee; and all dealings relating to any Guaranteed Amounts between
the  Borrower  or  the  Guarantor,  on  the  one  hand,  and the Lenders and the
Administrative  Agent,  on the other, shall likewise be conclusively presumed to
have  been  had  or  consummated in reliance upon this Guarantee.  The Guarantor
waives diligence, presentment, protest, demand for payment and notice of default
or  nonpayment  to  or  upon  the  Borrower or the Guarantor with respect to the
Guaranteed  Amounts.    Except  as  otherwise  provided  in  Section  1(d), this
Guarantee  shall  be  construed  as  a  continuing,  absolute  and unconditional
guarantee  of  payment  to  the  extent  provided  herein  without regard to any
circumstance  whatsoever (with or without notice to or knowledge of the Borrower
or  the  Guarantor)  which  constitutes, or might be construed to constitute, an
equitable  or  legal discharge of the Borrower for the Guaranteed Amounts, or of
the  Guarantor  under  this  Guarantee,  in bankruptcy or in any other instance.
Except  as  otherwise  provided  in Section 1(d), this Guarantee shall remain in
full force and effect and be binding in accordance with and to the extent of its
terms upon the Guarantor and its successors and assigns thereof, and shall inure
to  the  benefit  of  the  Administrative  Agent  and the Lenders and respective
successors, indorsees, transferees and assigns, until all Obligations shall have
been  satisfied  by  payment  in  full.

          .       Reinstatement.  This Guarantee shall continue to be effective,
or  be  reinstated,  as  the  case  may  be, if at any time payment, or any part
thereof, of any Guaranteed Amounts is rescinded or must otherwise be restored or
returned  by  the  Administrative  Agent  and  the  Lenders upon the bankruptcy,
insolvency, liquidation or reorganization of the Borrower or upon or as a result
of  the  appointment  of a receiver, intervenor or conservator of, or trustee or
similar  officer  for,  the Borrower or any substantial part of its property, or
otherwise,  all  as  though  such  payments  had  not  been  made.

          .          Payments.   The Guarantor hereby agrees that any Guaranteed
Amounts will be paid to the Administrative Agent and the Lenders without set-off
or  counterclaim.

          .        Representations and Warranties.  The Guarantor represents and
warrants  to  the  Administrative  Agent  and  the  Lenders  that:

          ()     the Guarantor is a corporation duly organized, validly existing
and  in  good  standing under the laws of the jurisdiction of its incorporation;

          ()         the Guarantor has the corporate power and authority and the
legal  right  to execute and deliver, and to perform its obligations under, this
Guarantee  and  the  Cash  Collateral  Agreement,  and  has  taken all necessary
corporate  action  to  authorize its execution, delivery and performance of this
Guarantee  and  the  Cash  Collateral  Agreement  and  the grant of the security
interest  contemplated  by  the  Cash  Collateral  Agreement;
          ()          each  of  this Guarantee and the Cash Collateral Agreement
constitutes  a  legal, valid and binding obligation of the Guarantor enforceable
in  accordance  with  its  terms,  except as affected by bankruptcy, insolvency,
fraudulent  conveyance,  reorganization,  moratorium  and  other  similar  laws
relating to or affecting the enforcement of creditors' rights generally, general
equitable  principles  and  an  implied covenant of good faith and fair dealing;

          ()       the execution, delivery and performance of this Guarantee and
the  Cash  Collateral Agreement will not violate any provision of any applicable
law  or  contractual  obligation  of  the  Guarantor;  and

          ()     no consent or authorization of, filing with, or other act by or
in  respect  of,  any arbitrator or governmental authority and no consent of any
other  person (including, without limitation, any stockholder or creditor of the
Guarantor)  is required in connection with the execution, delivery, performance,
validity  or  enforceability of this Guarantee or the Cash Collateral Agreement.

          .          Notices.   All notices, requests and demands to or upon the
Administrative  Agent and the Lenders, or the Guarantor to be effective shall be
in  writing  (or by fax or similar electronic transfer confirmed in writing) and
shall  be  deemed  to have been duly given or made (1) when delivered by hand or
(2)  if  given  by  mail,  when deposited in the mails by certified mail, return
receipt  requested,  or  (3) if by fax or similar electronic transfer, when sent
and  receipt has been confirmed, addressed to the address or transmission number
set  forth  under  the  signature  of  the  parts to whom notice is being given.

          ()      if to the Guarantor, at its address or transmission number for
notices  set  forth  with  its  signature  hereto;

          ()      if to the Administrative Agent or the  Lenders, as provided in
the  Credit  Agreement.

Either  the  Administrative  Agent,  the Lenders or the Guarantor may change its
address and transmission numbers for notices by notice in the manner provided in
this  Section.

          .          Severability.    Any  provision  of this Guarantee which is
prohibited  or unenforceable in any jurisdiction shall, as to such jurisdiction,
be  ineffective  to  the  extent of such prohibition or unenforceability without
invalidating  the  remaining  provisions  hereof,  and  any  such prohibition or
unenforceability  in  any  jurisdiction  shall  not  invalidate  or  render
unenforceable  such  provision  in  any  other  jurisdiction.

          .         Integration.  This Guarantee represents the agreement of the
Guarantor with respect to the subject matter hereof and there are no promises or
representations  by  the  Administrative  Agent  and the Lenders relative to the
subject  matter  hereof  not  reflected  herein.
          .         Amendments in Writing; No Waiver; Cumulative Remedies.    ()
None  of  the  terms  or  provisions  of  this Guarantee may be waived, amended,
supplemented  or  otherwise  modified except by a written instrument executed by
the  Guarantor and the Administrative Agent, provided that any provision of this
Guarantee  may be waived by the Lenders in a letter or agreement executed by the
Administrative Agent or by facsimile transmission from the Administrative Agent.

          ()          The  Lenders  shall  not  by  any act (except by a written
instrument  pursuant  to paragraph 11(a) hereof), delay, indulgence, omission or
otherwise  be  deemed  to  have  waived any right or remedy hereunder or to have
acquiesced  in  any  default  or event of default or in any breach of any of the
terms  and  conditions  hereof.    No  failure  to  exercise,  nor  any delay in
exercising,  on the part of the Lenders, any right, power or privilege hereunder
shall  operate as a waiver thereof.  No single or partial exercise of any right,
power  or  privilege  hereunder  shall  preclude  any  other or further exercise
thereof or the exercise of any other right, power or privilege.  A waiver by the
Lenders  of  any  right  or  remedy  hereunder  on any one occasion shall not be
construed as a bar to any right or remedy which the Lenders would otherwise have
on  any  future  occasion.

          ()      The rights and remedies herein provided are cumulative, may be
exercised  singly  or  concurrently and are not exclusive of any other rights or
remedies  provided  by  law.

          .       Section Headings.  The section headings used in this Guarantee
are  for  convenience  of  reference only and are not to affect the construction
hereof  or  be  taken  into  consideration  in  the  interpretation  hereof.

          .        Successors and Assigns.  This Guarantee shall be binding upon
the  successors  and  assigns of the Guarantor and shall inure to the benefit of
the  Administrative  Agent  and  the  Lenders  and their successors and assigns.

          .      Governing Law; Jurisdiction; Consent to Service of Process.  ()
This  Guarantee  shall  in  all  respects  be  construed  in accordance with and
governed  by  the  law  of  the  State  of New York without giving effect to the
conflicts  of  law  principles  thereof.

          ()       The Guarantor hereby irrevocably and unconditionally submits,
for  itself  and  its  property, to the nonexclusive jurisdiction of the Supreme
Court  of  the  State  of  New York sitting in New York County and of the United
States  District  Court  of the Southern District of New York, and any appellate
court  from  any thereof, in any action or proceeding arising out of or relating
to  this  Guarantee  or  the  Cash  Collateral  Agreement, or for recognition or
enforcement  of  any  judgment,  and  the  Guarantor  hereby  irrevocably  and
unconditionally  agrees  that  all  claims  in  respect  of  any  such action or
proceeding  may be heard and determined in such New York State or, to the extent
permitted  by  law,  in  such  Federal court.  The Guarantor agrees that a final
judgment  in  any  such  action  or  proceeding  shall  be conclusive and may be
enforced  in  other jurisdictions by suit on the judgment or in any other manner
provided  by  law.    Nothing in this Guarantee or the Cash Collateral Agreement
shall affect any right that the Administrative Agent or any Lender may otherwise
have  to  bring  any action or proceeding relating to this Guarantee or the Cash
Collateral  Agreement  against  the Guarantor or its properties in the courts of
any  jurisdiction.

          ()     The Guarantor hereby irrevocably and unconditionally waives, to
the  fullest extent it may legally and effectively do so, any objection which it
may  now  or  hereafter  have  to  the  laying  of  venue of any suit, action or
proceeding  arising  out of or relating to this Guarantee or the Cash Collateral
Agreement  in  any court referred to in paragraph (b) of this Section and hereby
irrevocably  waives,  to  the fullest extent permitted by law, the defense of an
inconvenient  forum  to the maintenance of such action or proceeding in any such
court.

          ()     The Guarantor irrevocably consents to service of process in the
manner  provided  for notices to the Guarantor above.  Nothing in this Guarantee
or  the  Cash  Collateral  Agreement  will affect the right of any party to this
Guarantee  or the Cash Collateral Agreement to serve process in any other manner
permitted  by  law.

          .          WAIVER  OF JURY TRIAL.  THE GUARANTOR HEREBY WAIVES, TO THE
FULLEST  EXTENT PERMITTED BY APPLICABLE LAW, ANY RIGHT IT MAY HAVE TO A TRIAL BY
JURY  IN  ANY LEGAL PROCEEDING DIRECTLY OR INDIRECTLY ARISING OUT OF OR RELATING
TO  THIS  GUARANTEE  OR  THE  CASH  COLLATERAL  AGREEMENT  OR  THE  TRANSACTIONS
CONTEMPLATED HEREBY (WHETHER BASED ON CONTRACT, TORT OR ANY OTHER THEORY).   THE
GUARANTOR  (A) CERTIFIES THAT NO REPRESENTATIVE, AGENT OR ATTORNEY OF ANY LENDER
HAS  REPRESENTED,  EXPRESSLY  OR  OTHERWISE,  THAT SUCH LENDER WOULD NOT, IN THE
EVENT  OF  LITIGATION, SEEK TO ENFORCE THE FOREGOING WAIVER AND (B) ACKNOWLEDGES
THAT  THE  LENDERS  HAVE  BEEN INDUCED TO MAKE THE LOANS AND OTHER EXTENSIONS OF
CREDIT  CONTEMPLATED  BY  THIS  GUARANTEE  AND THE CASH COLLATERAL AGREEMENT BY,
AMONG  OTHER  THINGS,  THE  WAIVERS  AND  CERTIFICATIONS  IN  THIS  SECTION.


<PAGE>

          IN  WITNESS  WHEREOF,  the undersigned has caused this Guarantee to be
duly  executed  and  delivered  by its duly authorized officer as of the day and
year  first  above  written.


                                       KEYSTONE,  INC.


                                       By /s/ David G. Brown

                                       Title VP CFO

                                       Address  for  Notices:

                                       201  Main  Street
                                       Fort  Worth,  Texas  76102
                                       Attention:    Kevin  G.  Levy
                                       Fax:    817-338-2067