Investor Presentation March 2010

1. Investor Presentation March 2010 Ainsworth Lumber Co. Ltd.

2. Forward Looking Statement Certain statements and other information included in this presentation constitute forward-looking statements as defined under applicable securities legislation including but not limited to the slides entitled “Strategic Plan”, “Well Positioned for Value Appreciation – US West” and “Outlook”.  When used herein, words such as “estimates”, “plans”, “expects”, “anticipates” and “projections” and similar expressions are intended to identify forward-looking statements. Forward-looking statements are based on assumptions made by, and information available to, Ainsworth Lumber Co. Ltd. ("Ainsworth"). Investors are cautioned that such forward-looking statements involve risks and uncertainties. Important factors that could cause actual results to differ materially from those expressed or implied by such forward-looking statements include, without limitation, the future demand for Ainsworth's products, future sales volumes, efficiencies and operating costs, increases or decreases in the prices of Ainsworth's products, Ainsworth's future capital needs, including capital expenditures, future developments in Ainsworth's affairs or in the industries in which Ainsworth participates and other factors detailed from time to time in Ainsworth's periodic reports filed with Canadian securities regulators and other regulatory authorities.  Ainsworth has no intention or obligation to update or revise any forward-looking statements, whether as a result of new information, future events or otherwise, except as required by law. Non-GAAP Measures Except where otherwise indicated, the financial information in this presentation is determined on the basis of Canadian GAAP. “Adjusted EBITDA” is a non-GAAP measure, calculated as net income (loss) from continuing operations before amortization, gain (loss) on disposal of capital assets, finance expense, realized currency translation adjustments, foreign exchange gain (loss) on long-term debt, other foreign exchange gain (loss), income tax recovery and other non-recurring items. 2 Investor Presentation – March 2010

3. Ainsworth Overview • Founded in 1950 • Company was recapitalized in 2008 • Bond holders received 96% equity • Trade on the TSX “ANS” • Sell strand based engineered wood building products – Primarily Oriented Strand Board (OSB) • Sell products to North America and overseas • Executive Management Team • Rick Huff – President & CEO • Chris Davies – CFO • Robert Fouquet – VP, Sales • Terry Brennan – VP, Operations • Tim Ryan – VP, Woodlands • Vyvian Burton – VP, Human Resources 3 Investor Presentation – March 2010 Investor Presentation – March 2010

4. US Housing Starts U.S. Housing ForecastSingle Family & Multifamily Only* (APA August 2009) Underlying trend in fundamental demand approximately 1.6 million starts 1.475 1.2 1.0 0.906 0.675 0.545 *Add approx 80,000 manufactured homes to get total housing production in the U.S. Investor Presentation – March 2010

5. OSB Industry Composition 5 Investor Presentation – March 2010

6. Operating Footprint OSB • Potential annual capacity of 2.66 billion sf • 1.61 billion sf in operation today • Eliminated 1.13 billion sf of high cost commodity production • Operating assets attractively located • Located near high-growth Western N. America regions & EWP partners • Good access to Japan and South East Asia • Flexible mill technology can produce for domestic and overseas markets • Canadian mills very well-fibred & energy efficient • Experienced, reliable and safe workers across operating platform • Low sustaining capital requirements Facility Annual Capacity (mmsf 3/8”) OSB – Operating at Capacity • 100 Mile House, BC 440 • Grande Prairie, AB 690 • Barwick, ON 480 1,610 Incremental Capacity – Not Operating • High Level, AB(1) 430 • Grande Prairie, AB(2) 620 Total Potential Capacity 2,660 • (1) 50% of High Level Mill’s Capacity (2) Estimated one year to complete construction 6 Investor Presentation – March 2010

7. Post-Restructuring Strategy • Recapitalized July 2008 – Bondholders hold 96% of Equity • Rick Huff, President and CEO joined in January 2009 • Year One was very tactical, crisis management with limited long term strategic planning • Priority was to protect cash • 4 major objectives – year one • Close unproductive/unprofitable facilities • Identify and divest non-core assets • Reduce cash burn associated with permanently closed assets • Correct SG&A expenditures to be in line with industry • How did we do? • Closed and divested 5 unproductive, non-strategic mills & sold surplus forest license (total loss from discontinued operations in 2009 was $38 million) 7 Investor Presentation – March 2010

8. Looking Forward Strategy • Plan strategically to emerge from the cyclical downturn profitably and well positioned for growth • Transform the organization into an innovative and customer-focused provider of high-margin products • Value-added sales mix will significantly drive liquidity and provide the sustainability required to dampen the negative effects of future industry downturns • Increase value-added product production and decrease commodity sheathing • Continue corporate transformation and emphasize the drive for constant improvements • Maintain excellent record of workplace safety Investor Presentation – March 2010

9. Additional Capacity Options • High Level, Alberta – Restart • 860 mmsf designed capacity • Joint venture partner Grant Forest Product (50/50) • Indefinitely curtailed in December 2006 • Grande Prairie 2 – Complete Construction • Second line on Grande Prairie site • 600 mmsf designed capacity • Designed to produce both OSL and OSB • Construction suspended in 2006 9 Investor Presentation – March 2010

10. EWP – Well Positioned and Growing • Ainsworth is a preferred supplier of engineered wood products (EWPs) • Leading supplier of webstock and rim board in North America • Strategic relationships with wood I-joist producers & rim board distributors/customers • Competitive success through customized products, technical know-how and excellent customer service 10 Investor Presentation – March 2010

11. OSB Usage in Residential Construction 11 Investor Presentation – March 2010

12. Well Positioned for Value Appreciation – U.S. West • Operating platform is attractively located near high-growth Western region • Strategic partners have strong footprint in key markets • OSB/OSL used in increasing number of residential, commercial & industrial applications • Environmentally-friendly products • Additional capacity available to capture strengthening residential construction and new opportunities 12 Investor Presentation – March 2010

13. Japan – Diversification away from North America • Ainsworth is the #1 supplier of OSB to Japan and is aggressively growing that position • > 70% share of OSB imports today • Longstanding relationships with growth customers • Japan is world’s 2nd largest wood-frame construction market • Supply shifts and product acceptance provide significant OSB growth opportunities 13 Investor Presentation – March 2010

14. ______ ____ ___ ____ _________ Balance Sheet and Other Statistics 16 Investor Presentation – March 2010

15. Debt Summary Investor Presentation – March 2010

16. Outlook • Secure sustainable timber supplies • Anticipate modest increase in demand in 2010 • Expect oscillating OSB prices as price increases are followed by supply increases as mills become economically viable • We will continue to have a very disciplined use of cash • Internal cost improvement will continue to be a key focus • We have additional capacity available for growth • We have substantial liquidity to manage through the cycle Investor Presentation – March 2010

17. Questions & Answers 19 Investor Presentation – March 2010

18. Balance Sheet and Other Statistics - Appendix Investor Presentation – March 2010