Exhibit 99.1 NEWS RELEASE TREX COMPANY REPORTS FOURTH QUARTER AND FULL YEAR 2023 RESULTS —Strong Fourth Quarter Sales Cap a Year of Resilient Consumer Demand for Trex Decking & Railing— —Full Year Gross Margin Expanded By 480 Basis Points— —2024 Guidance Anticipates Double-Digit Sales Growth and Further Margin Expansion— WINCHESTER, Va.—February 26, 2024— Trex Company, Inc. (NYSE:TREX) (Trex or Company), the world’s #1 brand of high-performance, low-maintenance and eco-friendly decking and railing and a lea ...