320 Bay Street, 14th Floor Toronto, ON M5H 4A6 www.computershare.com Security Class Holder Account Number Form of Proxy - Annual General and Special Meeting to be held on April 22, 2026 This Form of Proxy is solicited by and on behalf of Management. Notes to proxy 1. Every holder has the right to appoint some other person or company of their choice, who need not be a holder, to attend and act on their behalf at the meeting or any adjournment or postponement thereof. If you wish to appoint a person or company other than the Management Nominees whose names are printed herein, please insert the name of your chosen proxyholder in the space provided (see reverse). 2. If the securities are registered in the name of more than one owner (for example, joint ownership, trustees, executors, etc.), then all those registered should sign this proxy. If you are voting on behalf of a corporation or another individual you may be required to provide documentation evidencing your power to sign this proxy with signing capacity stated. If you are voting on behalf of a corporation you are required to provide your name and designation of office, e.g., ABC Inc. per John Smith, President. 3. This proxy should be signed in the exact manner as the name(s) appear(s) on the proxy. 4. If a date is not inserted in the space provided on the reverse of this proxy, it will be deemed to bear the date on which it was mailed to the holder by Management. 5. The securities represented by this proxy will be voted as directed by the holder, however, if such a direction is not made in respect of any matter, and the proxy appoints the Management Nominees listed on the reverse, this proxy will be voted as recommended by Management. 6. The securities represented by this proxy will be voted in favour, or withheld from voting, or voted against each of the matters described herein, as applicable, in accordance with the instructions of the holder, on any ballot that may be called for. If you have specified a choice with respect to any matter to be acted on, the securities will be voted accordingly. 7. This proxy confers discretionary authority in respect of amendments or variations to matters identified in the Notice of Meeting and Management Information Circular or other matters that may properly come before the meeting or any adjournment or postponement thereof, unless prohibited by law. 8. This proxy should be read in conjunction with the accompanying documentation provided by Management. Proxies submitted must be received by 11:00 am (Vancouver Time), on April 20, 2026. VOTE USING THE TELEPHONE OR INTERNET 24 HOURS A DAY 7 DAYS A WEEK! To Vote Using the Telephone • Call the number listed BELOW from a touch tone telephone. 1-866-732-VOTE (8683) Toll Free To Vote Using the Internet • Go to the following web site: www.investorvote.com • Smartphone? Scan the QR code to vote now. To Receive Documents Electronically • You can enroll to receive future securityholder communications electronically by visiting www.investorcentre.com. If you vote by telephone or the Internet, DO NOT mail back this proxy. Voting by mail may be the only method for securities held in the name of a corporation or securities being voted on behalf of another individual. Voting by mail or by Internet are the only methods by which a holder may appoint a person as proxyholder other than the Management Nominees named on the reverse of this proxy. Instead of mailing this proxy, you may choose one of the two voting methods outlined above to vote this proxy. To vote by telephone or the Internet, you will need to provide your CONTROL NUMBER listed below. CONTROL NUMBER ------- Fold ------- Fold

------- Fold ------- Fold Appointment of Proxyholder I/We being holder(s) of securities of West Fraser Timber Co. Ltd. (the “Company”) hereby appoint: Hank Ketcham, Chair of the Board, or failing this person, Sean McLaren, President and Chief Executive Officer of the Company (the “Management Nominees”) OR Print the name of the person you are appointing if this person is someone other than the Management Nominees listed herein. as my/our proxyholder with full power of substitution and to attend, act and to vote for and on behalf of the holder in accordance with the following direction (or if no directions have been given, as the proxyholder sees fit) and on all other matters that may properly come before the Annual General and Special Meeting of shareholders of the Company to be held at Suite 1500 – 885 West Georgia Street, Vancouver, British Columbia on April 22, 2026 at 11:00 am (Vancouver Time), and at any adjournment or postponement thereof. VOTING RECOMMENDATIONS ARE INDICATED BY HIGHLIGHTED TEXT OVER THE BOXES. 1. Number of Directors To set the number of Directors at eleven (11). For Against 2. Election of Directors 01. Henry H. (Hank) Ketcham For Withhold 02. Doyle N. Beneby For Withhold 03. Eric L. Butler For Withhold 04. Reid E. Carter 05. John N. Floren 06. Ellis Ketcham Johnson 07. Brian G. Kenning 08. Marian Lawson 09. Sean P. McLaren 10. Colleen M. McMorrow 11. Gillian D. Winckler 3. Appointment of Auditors Appointment of PricewaterhouseCoopers LLP as the Auditors of the Company for the ensuing year and authorizing the Directors to fix their remuneration. For Withhold 4. Advisory “Say on Pay” Resolution To pass an advisory resolution to approve the Company’s approach to executive compensation, as more particularly described under “Advisory Resolution on the Company’s Approach to Executive Compensation (Say on Pay)” in the accompanying Information Circular. For Against 5. Reconfirmation and Continuation of Shareholder Rights Plan Resolution To pass an ordinary resolution approving the reconfirmation and continuation of the Shareholder Rights Plan, without amendment, as more particularly described under “Resolution to Reconfirm and Continue the Shareholder Rights Plan” in the accompanying Information Circular. For Against Signature of Proxyholder I/We authorize you to act in accordance with my/our instructions set out above. I/We hereby revoke any proxy previously given with respect to the Meeting. If no voting instructions are indicated above, and the proxy appoints the Management Nominees, this Proxy will be voted as recommended by Management. If you are voting on behalf of a corporation you are required to provide your name and designation of office, e.g., ABC Inc. per John Smith, President. Signature(s) Date Signing Capacity Interim Financial Statements - Mark this box if you would like to receive Interim Financial Statements and accompanying Management’s Discussion and Analysis by mail. Annual Financial Statements - Mark this box if you would like to receive the Annual Financial Statements and accompanying Management’s Discussion and Analysis by mail. If you are not mailing back your proxy, you may register online to receive the above financial report(s) by mail at www.computershare.com/mailinglist. 3 8 2 3 7 3 A R 1W X T Q

WEST FRASER TIMBER CO., LTD 6-K