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Proc-Type: 2001,MIC-CLEAR
Originator-Name: webmaster@www.sec.gov
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MIC-Info: RSA-MD5,RSA,
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<SEC-DOCUMENT>0001264385-05-000073.txt : 20050208
<SEC-HEADER>0001264385-05-000073.hdr.sgml : 20050208
<ACCEPTANCE-DATETIME>20050208161458
ACCESSION NUMBER:		0001264385-05-000073
CONFORMED SUBMISSION TYPE:	5
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20041231
FILED AS OF DATE:		20050208
DATE AS OF CHANGE:		20050208

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			LAFARGE NORTH AMERICA INC
		CENTRAL INDEX KEY:			0000716783
		STANDARD INDUSTRIAL CLASSIFICATION:	CEMENT, HYDRAULIC [3241]
		IRS NUMBER:				581290226
		STATE OF INCORPORATION:			MD
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		12950 WORLDGATE DR. SUITE 500
		CITY:			HERNDON
		STATE:			VA
		ZIP:			20170
		BUSINESS PHONE:		7034803600

	MAIL ADDRESS:	
		STREET 1:		12950 WORLDGATE DR. SUITE 500
		CITY:			HERNDON
		STATE:			VA
		ZIP:			20170

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			COLLOMB BERTRAND P
		CENTRAL INDEX KEY:			0001241924

	FILING VALUES:
		FORM TYPE:		5
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-08584
		FILM NUMBER:		05584209

	MAIL ADDRESS:	
		STREET 1:		61 RUE DES BELLES FEUILLEA
		CITY:			PARIS
		STATE:			I0
		ZIP:			75116
</SEC-HEADER>
<DOCUMENT>
<TYPE>5
<SEQUENCE>1
<FILENAME>primary_doc.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>5</documentType>

    <periodOfReport>2004-12-31</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <form3HoldingsReported>0</form3HoldingsReported>

    <form4TransactionsReported>0</form4TransactionsReported>

    <issuer>
        <issuerCik>0000716783</issuerCik>
        <issuerName>LAFARGE NORTH AMERICA INC</issuerName>
        <issuerTradingSymbol>LAF</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001241924</rptOwnerCik>
            <rptOwnerName>COLLOMB BERTRAND P</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>61 RUE DES BELLES FEUILLEA</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>PARIS</rptOwnerCity>
            <rptOwnerState>I0</rptOwnerState>
            <rptOwnerZipCode>75116</rptOwnerZipCode>
            <rptOwnerStateDescription>FRANCE</rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>Chairman of the Board</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2004-08-05</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>5</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>106</value>
                    <footnoteId id="F1"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>28.332</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>5514</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <footnotes>
        <footnote id="F1">These shares were acquired under the Lafarge North America Inc. Employee Stock Purchase Plan</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>William G. Miller, signed pursuant to authorization previously filed</signatureName>
        <signatureDate>2005-01-31</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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