Material Agreement (Form 8-K)

Item 1.01 Entry into a Material Definitive Agreement.

On February 26, 2026, Trex Company, Inc. (the "Company") entered into a Forward Share Repurchase Transaction Confirmation (the "Confirmation") with Wells Fargo Bank, National Association ("Wells Fargo"). The transaction constitutes an accelerated share repurchase ("ASR") program for shares of the Company's common stock (the "Common Stock").

Pursuant to the Confirmation, on February 27, 2026 (the "Prepayment Date"), the Company made a prepayment of $100,000,000 (the "Prepayment Amount") to Wells Fargo. In exchange, promptly after the Prepayment Date, the Company received an initial delivery of approximately 1.9 million shares of Common Stock (the "Initial Shares"), with such initial delivery valued at approximately 80% of the Prepayment Amount based on the February 26, 2026 closing price, subject to final settlement as described below.

The final number of shares to be repurchased under the ASR will be determined based on the volume-weighted average price of the Common Stock during the calculation period under Rule 10b-18 (as specified in the Confirmation), less a negotiated discount and subject to customary adjustments (the "Forward Price"). At final settlement, if the aggregate number of shares determined by dividing the Prepayment Amount by the Forward Price exceeds the Initial Shares, Wells Fargo will deliver additional shares of Common Stock to the Company. If the aggregate number of shares so determined is less than the Initial Shares, then, pursuant to settlement provisions in the Confirmation, the Company will deliver to Wells Fargo either (i) a cash payment or (ii) shares of Common Stock, at the Company's election and subject to the terms of the Confirmation.

The calculation period is scheduled to begin on February 27, 2026 and to conclude on May 21, 2026, subject to earlier termination or acceleration. Beginning on April 9, 2026, Wells Fargo may, in its discretion and subject to the terms of the Confirmation, accelerate the valuation date for all or part of the transaction. The Confirmation also contains customary provisions permitting adjustments, suspension of the calculation period, or early termination upon the occurrence of certain events, including specified market disruption events, changes in law, hedging disruptions and stock borrow events, announcements of certain acquisition or merger transactions, and if the trading price of the Common Stock is at or below a specified threshold during the relevant period.

During the calculation period and certain related settlement periods, the Company is subject to customary restrictions on repurchases of Common Stock and related securities, other than certain permitted transactions and purchases, as described in the Confirmation.

The Company funded the Prepayment Amount with borrowings under its line of credit. The ASR is intended to comply with Rule 10b5-1(c) under the Securities Exchange Act of 1934, as amended, and repurchases under the ASR will be effected in accordance with Rule 10b-18, subject to the terms and conditions of the Confirmation.

The foregoing description of the Confirmation does not purport to be complete and is qualified in its entirety by reference to the Confirmation, a copy of which is filed as Exhibit 10.1 to this Current Report on Form 8-K and incorporated herein by reference.

Item 8.01 Other Events.

The actual total number of shares repurchased under the ASR will be based on the Company's stock price during the applicable calculation period and is subject to the terms and conditions of the Confirmation, including potential adjustments, suspensions, or early termination as described above.

Item 9.01 Financial Statements and Exhibits.

(d) Exhibits