X0306 4 2015-02-18 0001069878 TREX CO INC TREX 0001201351 KAPLAN RONALD W C/O TREX COMPANY, INC. 160 EXETER DRIVE WINCHESTER VA 22603-8605 1 1 President and CEO Common Stock 2015-02-18 4 D 0 976 43.89 D 147717 D Common Stock 2015-02-18 4 F 0 2151 43.89 D 145566 D Common Stock 2015-02-18 4 A 0 13016 43.89 A 158582 D Common Stock 2015-02-18 4 A 0 13016 43.89 A 171598 D Common Stock 2015-02-19 4 F 0 2618 43.64 D 168980 D Represents net share difference between target performance-based shares and actual vested shares, based upon performance goals for the Company. 2,151 shares are being surrendered as allowed by the Company's 2005 Stock Incentive Plan to cover the payment of taxes currently due on previously granted restricted shares. This restricted stock award vests over a three-year period in three equal annual installments beginning on the first anniversary of the grant date. This restricted stock award is performance-based, and vests over a three-year period in three equal installments beginning on the first anniversary of the grant date. 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. 2,618 shares are being surrendered as allowed by the Company's 2005 Stock Incentive Plan to cover the payment of taxes currently due on previously granted restricted shares. /s/ William R. Gupp by power of attorney 2015-02-20