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                                                       Borden Ladner Gervais LLP
                                            Lawyers o Patent & Trade-mark Agents
                                                          1200 Waterfront Centre
                                              200 Burrard Street, P.O. Box 48600
                                                 Vancouver, B.C., Canada V7X 1T2
                                     tel: (604) 687-5744     fax: (604) 687-1415
                                                               www.blgcanada.com


(BORDEN LADNER GERVAIS LOGO)
                                                          February 18, 2005


Ainsworth Lumber Co. Ltd.
Suite 3194, Bentall 4
1055 Dunsmuir Street
Vancouver, British Columbia V7X 1L3


Dear Sirs/Mesdames:



                            AINSWORTH LUMBER CO. LTD.
    OFFERING OF US$275,000,000 PRINCIPAL AMOUNT 7 1/4% SENIOR NOTES DUE 2012
       AND US$175,000,000 PRINCIPAL AMOUNT SENIOR FLOATING NOTES DUE 2010

                  We have acted as Canadian counsel to Ainsworth Lumber Co. Ltd.
(the "COMPANY") in connection with the offering and sale by the Company of
US$275,000,000 aggregate principal amount of 7 1/4% Senior Notes due 2012 and
US$175,000,000 aggregate principal amount of Senior Floating Notes due 2010
(together, the "EXCHANGE NOTES") and Ainsworth Engineered Canada Limited
Partnership (the "GUARANTOR") in connection with the full and unconditional
guarantee by the Guarantor of the Exchange Notes (the "GUARANTEE"). The Exchange
Notes are being issued pursuant to an exchange offer (the "EXCHANGE OFFER") in
exchange for a like principal amount of issued and outstanding 7 1/4% Senior
Notes due 2012 and Senior Floating Notes due 2010 (together, the "ORIGINAL
NOTES"). The Original Notes were, and the Exchange Notes will be, issued under
an indenture between the Company and The Bank of New York, dated as of September
22, 2004 (as supplemented by a supplemental indenture dated as of January 10,
2005) (the "INDENTURE"), as contemplated by the Exchange and Registration Rights
Agreement, dated as of September 22, 2004, by and among the Company, Ainsworth
Engineered Corp. and Deutsche Bank Securities Inc. and Goldman, Sachs & Co. as
initial purchasers of the Original Notes.

                  This opinion is being furnished in accordance with item
601(b)(5) of Regulation S-K under the Securities Act of 1933, as amended (the
"ACT").

                  We have made, or caused to be made, such searches and
investigations, considered such matters of law and reviewed such other documents
and instruments as we have considered relevant and necessary for the purpose of
this opinion.









           Calgary  o  Montreal  o  Ottawa  o  Toronto  o  Vancouver

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                  We have assumed:

         (a)      the genuineness of all signatures, the authenticity of all
                  documents submitted to us as originals, and the conformity to
                  authentic original documents of all documents submitted to us
                  as certified or conformed copies or as photostatic copies,
                  facsimile transmissions or electronic correspondence;

         (b)      the due and valid execution and delivery of all agreements by
                  the parties thereto, other than the Company and the Guarantor,
                  as legal, valid and binding obligations of those parties;

         (c)      the accuracy and completeness of the records maintained by any
                  office of public record and of all representations, statements
                  and other matters of fact set out or referred to in
                  certificates or documents received from such offices of public
                  record; and

         (d)      the accuracy of the result of any printed or electronic search
                  of any office of public record and that the information
                  contained therein continues to be accurate as of the date
                  hereof.

                  We have not undertaken any independent investigations to
verify the accuracy or completeness of these assumptions. As to the various
questions of fact relevant to this opinion, information with respect to which is
in the possession of the Company, the Guarantor or other corporations or
persons, we have relied upon certificates, reports, opinions or representations
of or by an officer or officers of the Company, the Guarantor or such other
corporations or persons, as the case may be.

                  We have made no investigation of the laws of any jurisdiction
other than, and the opinions hereinafter expressed are confined to, the laws of
the Province of British Columbia (the "PROVINCE") and the federal laws of Canada
applicable in the Province (the "LAWS"). The opinions expressed herein are given
on the basis of the Laws as they exist on the date hereof. We assume no
responsibility to update our opinions if the Laws are, subsequent to the date
hereof, amended, revoked, revised or supplemented in any way which impacts on
the opinions contained herein.

                  Based upon and relying upon the foregoing and subject to the
qualifications set out below, we are of the opinion that:

         (i)      The Indenture has been duly authorized, executed and delivered
                  by the Company.

         (ii)     The execution and delivery of the Guarantee by the Company (in
                  its capacity as general partner of the Guarantor) on behalf of
                  the Guarantor has been duly authorized by the Guarantor.

         (iii)    The Company has the requisite power and authority to execute
                  and deliver the Exchange Notes and perform its obligations
                  thereunder.

         (iv)     The Company, in its capacity as general partner of the
                  Guarantor, has the requisite power and authority to execute
                  and deliver the Guarantee on behalf of the Guarantor, and the
                  Guarantor has the requisite power and authority to perform its
                  obligations thereunder.

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         (v)      The execution and delivery of the Exchange Notes by the
                  Company and the performance of its obligations thereunder,
                  have been duly authorized by all necessary corporate action on
                  the part of the Company.

         (vi)     A British Columbia or Canadian federal court of competent
                  jurisdiction (a "CANADIAN COURT") would give effect to the
                  choice of law of the State of New York ("NEW YORK LAW") as the
                  proper law governing the Indenture, the Exchange Notes and the
                  Guarantee, provided that such choice of law is bona fide (in
                  the sense that it was not made with a view to avoiding the
                  consequences of the laws of any other jurisdiction or for any
                  other improper purpose) and legal, and provided that such
                  choice of law is not contrary to public policy as that term is
                  applied by a Canadian Court ("CANADIAN PUBLIC POLICY"); and we
                  are not aware of any reasons under the Laws for avoiding the
                  choice of New York law to govern the Indenture, the Exchange
                  Notes and the Guarantee.

         (vii)    In an action in a Canadian court on the Indenture, a Canadian
                  Court would give effect to the appointment by the Company of
                  CT Corporation System as its agent to receive service of
                  process in the United States under the Indenture.

          (viii)  If the Indenture, the Exchange Notes or the Guarantee were
                  sought to be enforced in accordance with the laws applicable
                  thereto as chosen by the parties, namely, New York law, a
                  Canadian Court would, subject to paragraph (vi) above,
                  recognize the choice of New York law and, upon appropriate
                  evidence as to such law being adduced, apply such law,
                  provided that none of the provisions of the Indenture, the
                  Exchange Notes or the Guarantee, or of applicable New York
                  law, are contrary to Canadian Public Policy or illegal under
                  the laws of British Columbia, Canada, New York or the United
                  States; provided, however, that, in matters of procedure, the
                  laws of the jurisdiction of such Canadian Court would be
                  applied, and a Canadian Court would retain discretion to
                  decline to hear such action if it were contrary to Canadian
                  Public Policy for it to do so or if it were not the proper
                  forum to hear such an action or if concurrent proceedings were
                  being brought elsewhere.

         (ix)     The laws of the province of British Columbia would permit a
                  common law action to be brought in the Supreme Court of
                  British Columbia on a final, conclusive, subsisting,
                  unsatisfied, in personam judgment of a New York Court for a
                  sum certain, that is not impeachable as void or voidable under
                  New York law, within six years of that judgment. In such an
                  action the Court would not consider the merits of the New York
                  proceeding. Provided that the judgment creditor proved on a
                  balance of probabilities that:

                  (a)      the New York Court had jurisdiction under New York
                           law to deal with the New York proceeding and to
                           require the judgment debtor to appear before it;

                  (b)      either there was a real and substantial connection
                           between the parties, the cause of action and New York
                           or the judgment debtor had attorned to the
                           jurisdiction of the New York Court (and submission of
                           the Company to the jurisdiction of the New York Court
                           in the Indenture would be sufficient for that
                           purpose); and

                                     - 3 -
<PAGE>

                  (c)      the New York Court granted the New York judgment in
                           the judgment creditor's favour,

                  the Court would grant judgment enforcing the New York judgment
                  unless the judgment debtor proved on a balance of
                  probabilities that:

                  (a)      the New York judgment was obtained by fraud;

                  (b)      the New York judgment was obtained by a breach of
                           Canadian principles of natural justice with respect
                           to the New York Court's procedure;

                  (c)      the New York judgment was contrary to British
                           Columbia's public policy, that is, to its essential
                           conception of morality and justice; or

                  (d)      there was a manifest error on the face of the New
                           York judgment.

                  The Supreme Court of British Columbia would apply British
                  Columbia law with respect to the procedures for the
                  enforcement of the judgment. The Court's judgment would be in
                  Canadian dollars converted from the currency of the New York
                  judgment at the rate of exchange applicable on a conversion
                  date which would be in the discretion of the Court. If the New
                  York judgment included an interest component it would be
                  included in the principal amount of the British Columbia
                  judgment, with interest accruing on the total from the date of
                  the British Columbia judgment at the British Columbia
                  post-judgment interest rate, which is now 3.75%.

         (x)      We have no reason to believe that courts of British Columbia
                  would consider the enforcement of a judgment given by a court
                  of competent jurisdiction for payment of principal, interest
                  and premium, if any, under the Exchange Notes to be
                  inconsistent with Canadian Public Policy or constitute,
                  directly or indirectly, the enforcement of foreign revenue,
                  expropriatory or penal laws.

                  Our opinions expressed herein are subject to the following
                  qualifications:

         (i)      the enforceability of any agreement may be limited by
                  bankruptcy, reorganization, winding-up, insolvency,
                  moratorium, arrangement, fraudulent preference and conveyance,
                  assignment and preference and other similar laws of general
                  application affecting the enforcement of creditor's rights;

         (ii)     no opinion is given as to the enforceability of any term
                  providing for the severance of void, illegal or unenforceable
                  provisions from the remaining provisions of an agreement;

         (iii)    no opinion is given as to the enforceability of any term
                  providing that modifications, amendments or waivers are not
                  binding unless in writing;

         (iv)     no opinion is given with respect to rights to indemnity and
                  contribution;

                                     - 4 -
<PAGE>

         (v)      the enforceability of the obligations of a party under any
                  agreement is subject to general principles of equity,
                  including, without limitation:

                  (a)      concepts of materiality, reasonableness, good faith
                           and fair dealing in performance and enforcement of a
                           contract required of the party seeking its
                           enforcement;

                  (b)      the discretion exercisable by a court with respect to
                           equitable remedies, such as specific performance and
                           injunction;

                  (c)      the discretion exercisable by a court with respect to
                           stays of enforcement proceedings and execution of
                           judgments;

                  (d)      the effect of vitiating factors, such as mistake,
                           misrepresentation, fraud, duress or undue influence;
                           and

                  (e)      the discretion of a court with respect to the
                           enforcement of provisions in an agreement to the
                           effect that certain factual or legal determinations,
                           calculations or certificates will be conclusive and
                           binding;

         (vi)     a court may reserve to itself the right to decline
                  jurisdiction in any action if the court is an inconvenient
                  forum to hear the action or if concurrent proceedings are
                  being brought elsewhere, notwithstanding any waiver of the
                  right to raise such objection or defence thereto;

         (vii)    the right to exercise any unilateral or unfettered discretion
                  pursuant to an agreement will not prevent a court from
                  requiring such discretion to be exercised reasonably; and

         (viii)   the recoverability of costs and expenses may be limited to
                  those a court considers to be reasonably incurred, the costs
                  and expenses incidental to all court proceedings are in the
                  discretion of the court and the court has the discretion to
                  determine by whom and to what extent these costs shall be
                  paid.

                  We hereby consent to the filing of this opinion with the
Securities and Exchange Commission (the "COMMISSION") as an exhibit to the
Registration Statement filed with the Commission in connection with the Exchange
Offer. We also consent to the reference to our firm under the caption "Legal
Matters" in the Registration Statement. In giving this consent, we do not
thereby admit that we are included in the category of persons whose consent is
required under Section 7 of the Act or the rules and regulations of the
Commission.

                                      Yours truly,

                                      /s/ Borden Ladner Gervais LLP





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