-----BEGIN PRIVACY-ENHANCED MESSAGE-----
Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
Originator-Key-Asymmetric:
 MFgwCgYEVQgBAQICAf8DSgAwRwJAW2sNKK9AVtBzYZmr6aGjlWyK3XmZv3dTINen
 TWSM7vrzLADbmYQaionwg5sDW3P6oaM5D3tdezXMm7z1T+B+twIDAQAB
MIC-Info: RSA-MD5,RSA,
 KHUxKW63PVCXORUCtLceRoT75GR06Dxj4SF3sGnX2gX8PLrI/yqR4L7fnaNCYv8P
 MB+9Mk22bbV9fXC+qDJ5nQ==

<SEC-DOCUMENT>0001104659-07-015535.txt : 20070301
<SEC-HEADER>0001104659-07-015535.hdr.sgml : 20070301
<ACCEPTANCE-DATETIME>20070301161439
ACCESSION NUMBER:		0001104659-07-015535
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20070227
FILED AS OF DATE:		20070301
DATE AS OF CHANGE:		20070301

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			ELKCORP
		CENTRAL INDEX KEY:			0000032017
		STANDARD INDUSTRIAL CLASSIFICATION:	ASPHALT PAVING & ROOFING MATERIALS [2950]
		IRS NUMBER:				751217920
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			0630

	BUSINESS ADDRESS:	
		STREET 1:		14911 QUORUM DRIVE
		STREET 2:		SUITE 600
		CITY:			DALLAS
		STATE:			TX
		ZIP:			75254-1491
		BUSINESS PHONE:		9728510500

	MAIL ADDRESS:	
		STREET 1:		14911 QUORUM DRIVE
		STREET 2:		SUITE 600
		CITY:			DALLAS
		STATE:			TX
		ZIP:			75254-1491

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	ELCOR CORP
		DATE OF NAME CHANGE:	19920703

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	ELCOR CHEMICAL CORP
		DATE OF NAME CHANGE:	19761119

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			BUILDING MATERIALS CORP OF AMERICA
		CENTRAL INDEX KEY:			0000927314
		STANDARD INDUSTRIAL CLASSIFICATION:	ASPHALT PAVING & ROOFING MATERIALS [2950]
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-05341
		FILM NUMBER:		07663539

	BUSINESS ADDRESS:	
		STREET 1:		1361 ALPS RD
		CITY:			WAYNE
		STATE:			NJ
		ZIP:			07470
		BUSINESS PHONE:		2016283000

	MAIL ADDRESS:	
		STREET 1:		1361 ALPS ROAD
		CITY:			WAYNE
		STATE:			NJ
		ZIP:			07470
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>a4.xml
<DESCRIPTION>4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2007-02-27</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000032017</issuerCik>
        <issuerName>ELKCORP</issuerName>
        <issuerTradingSymbol>ELK</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0000927314</rptOwnerCik>
            <rptOwnerName>BUILDING MATERIALS CORP OF AMERICA</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>1361 ALPS ROAD</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>WAYNE</rptOwnerCity>
            <rptOwnerState>NJ</rptOwnerState>
            <rptOwnerZipCode>07470</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2007-02-27</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>296545</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>43.50</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>19007781</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Footnote</value>
                    <footnoteId id="F1"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2007-02-28</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>63947</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>43.50</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>19071728</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Footnote</value>
                    <footnoteId id="F1"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2007-03-01</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>2012780</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>43.5</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>21084508</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Footnote</value>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">Represents shares acquired via the notice of guarantee delivery period for the tender offer by BMCA Acquisition Sub Inc. (&quot;Purchaser&quot;), a wholly owned subsidiary of BMCA Acquisition Inc. (&quot;Parent&quot;), which is a wholly owned subsidiary of Building Materials Corporation of America.</footnote>
        <footnote id="F2">Represents shares issued pursuant to the Top-Up Option, pursuant to the Agreement and Plan of Merger, dated as of February 9, 2007, by and among Parent, Purchaser and ElkCorp.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Roger Assad, Vice President - Law and Secretary</signatureName>
        <signatureDate>2007-03-01</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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