DEFA14A

DEFA14A 1 2026_notice_and_access.htm DEFA14A DEFA14A

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 14A

Proxy Statement Pursuant to Section 14(a) of the Securities

Exchange Act of 1934

Filed by the Registrant ☒

Filed by a Party other than the Registrant ☐

Check the appropriate box:

☐ Preliminary Proxy Statement

☐ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2))

☐ Definitive Proxy Statement

☒ Definitive Additional Materials

☐ Soliciting Material Pursuant to §240.14a-12

Trex Company, Inc.

(Name of Registrant as Specified In Its Charter)

(Name of Person(s) Filing Proxy Statement, if other than the Registrant)

Payment of Filing Fee (Check all boxes that apply):

☒ No fee required

☐ Fee paid previously with preliminary materials

☐ Fee computed on table in exhibit required by Item 25(b) per Exchange Act Rules 14a-6(i)(1) and 0-11

TREX R VOTE Online Go to www.investorvote.com/TREX or scan the QR code — login details are located in the shaded bar below. Votes submitted electronically must be received by April 27, 2026 at 11:59 P.M., Eastern Time. Stockholder Meeting Notice Important Notice Regarding the Availability of Proxy Materials for the Trex Company, Inc. Stockholder Meeting to be Held on April 28, 2026 Under Securities and Exchange Commission rules, you are receiving this notice that the proxy materials for the annual stockholders’ meeting are available on the Internet. Follow the instructions below to view the materials and vote online or request a copy. The items to be voted on and location of the annual meeting are on the reverse side. Your vote is important! This communication presents only an overview of the more complete proxy materials that are available to you on the Internet. We encourage you to access and review all of the important information contained in the proxy materials before voting. The 2026 proxy statement and 2025 annual report to stockholders are available at: www.investorvote.com/TREX Easy Online Access — View your proxy materials and vote. Step 1: Go to www.investorvote.com/TREX. Step 2: Click on the icon on the right to view meeting materials. Step 3: Return to the investorvote.com window and follow the instructions on the screen to log in. Step 4: Make your selections as instructed on each screen for your delivery preferences. Step 5: Vote your shares. When you go online, you can also help the environment by consenting to receive electronic delivery of future materials. Obtaining a Copy of the Proxy Materials – If you want to receive a copy of the proxy materials, you must request one. There is no charge to you for requesting a copy. Please make your request as instructed on the reverse side on or before April 17, 2026 to facilitate timely delivery. 2NOT 048OQB

Stockholder Meeting Notice Stockholders of record as of the Record Date are encouraged and cordially invited to attend the Annual Meeting. Directions to attend the annual meeting where you may vote in person can be found on our website, http://www.trex.com/proxy. Trex Company, Inc.’s Annual Meeting of Stockholders will be held on April 28, 2026 at Trex University, 331 Apple Valley Road, Winchester, Virginia 22602, at 9:00 A.M. Eastern Time. Proposals to be voted on at the meeting are listed below along with the Board of Directors’ recommendations. The Board of Directors recommends a vote FOR all the nominees listed and FOR Proposals 2 and 3: 1. Election of Directors. 2. Non-binding advisory vote on executive compensation (“say-on-pay”). 3. Ratification of the appointment of Ernst & Young LLP as our independent registered public accounting firm for the 2026 fiscal year. PLEASE NOTE – YOU CANNOT VOTE BY RETURNING THIS NOTICE. To vote your shares you must go online or request a paper copy of the proxy materials to receive a proxy card. If you wish to attend and vote at the meeting, please bring this notice with you. Here’s how to order a copy of the proxy materials and select delivery preferences: Current and future delivery requests can be submitted using the options below. If you request an email copy, you will receive an email with a link to the current meeting materials. PLEASE NOTE: You must use the number in the shaded bar on the reverse side when requesting a copy of the proxy materials. — Internet – Go to www.investorvote.com/TREX. — Phone – Call us free of charge at 1-866-641-4276. — Email – Send an email to investorvote@computershare.com with “Proxy Materials Trex Company, INC.” in the subject line. Include your full name and address, plus the number located in the shaded bar on the reverse side, and state that you want a paper copy of the meeting materials. To facilitate timely delivery, requests for a paper copy of proxy materials must be received by April 17, 2026.

SEC Form DEFA14A filed by Trex Company Inc.