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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
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 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 C7uQSVx+ldpNaXwa0fufBry73Dx7VRlDeqYWndUPXJlUC1My1AzDXLxd4PysjRbq
 zWz+YQO4dS4XhD6c048fzA==

<SEC-DOCUMENT>0001069878-03-000060.txt : 20030716
<SEC-HEADER>0001069878-03-000060.hdr.sgml : 20030716
<ACCEPTANCE-DATETIME>20030716122823
ACCESSION NUMBER:		0001069878-03-000060
CONFORMED SUBMISSION TYPE:	3
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20030711
FILED AS OF DATE:		20030716

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			FLETCHER PAUL D
		CENTRAL INDEX KEY:			0001145087

	FILING VALUES:
		FORM TYPE:		3
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-14649
		FILM NUMBER:		03788735

	BUSINESS ADDRESS:	
		STREET 1:		160 EXETER DR
		CITY:			WINCHESTER
		STATE:			VA
		ZIP:			22603-8605
		BUSINESS PHONE:		5405426939

	FORMER NAME:	
		FORMER CONFORMED NAME:	FLETCHER PAUL
		DATE OF NAME CHANGE:	20010717

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			TREX CO INC
		CENTRAL INDEX KEY:			0001069878
		STANDARD INDUSTRIAL CLASSIFICATION:	LUMBER & WOOD PRODUCTS (NO FURNITURE) [2400]
		IRS NUMBER:				541910453
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		20 CAMERON ST
		CITY:			WINCHESTER
		STATE:			VA
		ZIP:			22801
		BUSINESS PHONE:		5406784070

	MAIL ADDRESS:	
		STREET 1:		20 CAMERON ST
		CITY:			WINCHESTER
		STATE:			VA
		ZIP:			22801
</SEC-HEADER>
<DOCUMENT>
<TYPE>3
<SEQUENCE>1
<FILENAME>c0001145087d20030716f3f.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<ownershipDocument><schemaVersion>X0101</schemaVersion>    <documentType>3</documentType><periodOfReport>2003-07-11</periodOfReport><noSecuritiesOwned>0</noSecuritiesOwned><issuer><issuerCik>0001069878</issuerCik><issuerName>TREX CO INC</issuerName>        <issuerTradingSymbol>TWP</issuerTradingSymbol></issuer><reportingOwner><reportingOwnerId><rptOwnerCik>0001145087</rptOwnerCik><rptOwnerName>FLETCHER PAUL D</rptOwnerName></reportingOwnerId><reportingOwnerAddress><rptOwnerStreet1>  </rptOwnerStreet1><rptOwnerStreet2>  </rptOwnerStreet2><rptOwnerCity>  </rptOwnerCity><rptOwnerState>  </rptOwnerState><rptOwnerZipCode>  </rptOwnerZipCode></reportingOwnerAddress><reportingOwnerRelationship><isDirector>0</isDirector><isOfficer>1</isOfficer><isTenPercentOwner>0</isTenPercentOwner><isOther>0</isOther><officerTitle>Senior VP and CFO</officerTitle><otherText></otherText></reportingOwnerRelationship></reportingOwner><nonDerivativeSecurity><securityTitle><value>Common Stock</value></securityTitle><transactionAmounts><
transactionShares><value>40000</value></transactionShares></transactionAmounts><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnership><value></value></natureOfOwnership></ownershipNature></nonDerivativeSecurity><derivativeSecurity><securityTitle><value>Stock Options (Right to buy)</value></securityTitle><conversionOrExercisePrice><value>17.45</value></conversionOrExercisePrice><exerciseDate><value>2002-10-16</value><footnoteId id="F1"/></exerciseDate><expirationDate><value>2011-10-16</value></expirationDate><underlyingSecurity><underlyingSecurityTitle><value>Common Stock</value></underlyingSecurityTitle><underlyingSecurityShares><value>25000</value></underlyingSecurityShares></underlyingSecurity><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnership><value></value></natureOfOwnership></ownershipNature></derivativeSecurity><derivativeSecurity><securityTitle><value>Stock Options (Right to buy)</value></secur
ityTitle><conversionOrExercisePrice><value>20</value></conversionOrExercisePrice><exerciseDate><value>2003-02-21</value><footnoteId id="F1"/></exerciseDate><expirationDate><value>2012-02-21</value></expirationDate><underlyingSecurity><underlyingSecurityTitle><value>Common Stock</value></underlyingSecurityTitle><underlyingSecurityShares><value>11858</value></underlyingSecurityShares></underlyingSecurity><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnership><value></value></natureOfOwnership></ownershipNature></derivativeSecurity><derivativeSecurity><securityTitle><value>Stock Options (Right to buy)</value></securityTitle><conversionOrExercisePrice><value>35.95</value></conversionOrExercisePrice><exerciseDate><value>2004-02-25</value><footnoteId id="F1"/></exerciseDate><expirationDate><value>2013-02-25</value></expirationDate><underlyingSecurity><underlyingSecurityTitle><value>Common Stock</value></underlyingSecurityTitle><underlyingSecurityShares><value>726
1</value></underlyingSecurityShares></underlyingSecurity><ownershipNature><directOrIndirectOwnership><value>D</value></directOrIndirectOwnership><natureOfOwnership><value></value></natureOfOwnership></ownershipNature></derivativeSecurity><footnotes><footnote id="F1">The options become exercisable in four equal installments beginning on the date shown as Date Exercisable.</footnote></footnotes><ownerSignature><signatureName>Lynn E. MacDonald</signatureName><signatureDate>2003-07-16</signatureDate></ownerSignature></ownershipDocument>

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</SEC-DOCUMENT>
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