|Issuer:||TREX CO INC (TREX)|
|Original Submission Date:|
GUPP WILLIAM R.
C/O TREX COMPANY, INC.
160 EXETER DRIVE WINCHESTER, VA 22603-8605
|Title of Security||Transaction Date||2a. Deemed Execution Date||Transaction Code||Shares||Acquired or Disposed||Price per share||5. Amount of Securities Beneficially Owned Following Reported Transaction||6. Ownership Form Direct or Indirect||Nature of Indirect Ownership|
|Title of Derivative Security||Conversion or Exercise Price of Derivative Security||Transaction Date||Deemed Execution Date||Transaction Code||Number of Derivative Securities Acquired (A) or Disposed of (D)||Date Exercisable||Expiration Date||Title and Amount of Securities Underlying Derivative Security||Price of Derivative Security||Number of derivative Securities Beneficially Owned Following Reported Transaction(s)||Ownership Form: Direct (D) or Indirect (I)||Nature of Indirect Beneficial Ownership|
|STOCK APPRECIATION RIGHT||104.56||2021-02-17||deemed execution date||A||1,636 (a)||2022-02-17||2031-02-17||common stock 1,636||$104.56||1,636||direct|
|f1||this restricted stock unit vests over a three-year period in three equal annual installments beginning on the first anniversary of the grant date.|
|f2||this restricted stock unit 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.|
|f3||the stock appreciation right becomes exercisable in three equal installments beginning on the first anniversary of the grant date.|
|f4||represents net share difference between target performance-based shares and actual vested shares, based upon actual performance for the company.|
|f5||3,931 shares are being surrendered as allowed by the company's 2014 stock incentive plan to cover payment of taxes currently due on previously granted restricted stock units.|