X0508 4 2026-02-24 0001069878 TREX CO INC TREX 0002013330 Rudolph Jacob T. 2500 TREX WAY C/O TREX COMPANY, INC. WINCHESTER VA 22601 1 SVP, CHRO 0 Common Stock 2026-02-24 4 A 0 6321 41.45 A 33973 D Common Stock 2026-02-24 4 A 0 6321 41.45 A 40294 D This restricted stock unit award vests over a three-year period in three equal annual installments occurring March 1, 2027, March 1, 2028, and March 1, 2029. This restricted stock unit award is performance-based, and vests over a three-year period in three equal installments occurring March 1, 2027, March 1, 2028, and March 1, 2029. The number of shares set forth above is the target number of shares. The number of shares that will actually vest each year will be based upon performance against certain financial goals for the Company and will range from 0% to 200% of the target number of shares. /s/ Amy M. Fernandez by power of attorney 2026-02-25