-----BEGIN PRIVACY-ENHANCED MESSAGE-----
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>0001179110-09-014731.txt : 20091023
<SEC-HEADER>0001179110-09-014731.hdr.sgml : 20091023
<ACCEPTANCE-DATETIME>20091023145456
ACCESSION NUMBER:		0001179110-09-014731
CONFORMED SUBMISSION TYPE:	5
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20090930
FILED AS OF DATE:		20091023
DATE AS OF CHANGE:		20091023

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			BEACON ROOFING SUPPLY INC
		CENTRAL INDEX KEY:			0001124941
		STANDARD INDUSTRIAL CLASSIFICATION:	WHOLESALE-LUMBER & OTHER CONSTRUCTION MATERIALS [5030]
		IRS NUMBER:				000000000
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			0930

	BUSINESS ADDRESS:	
		STREET 1:		ONE LAKELAND PARK DRIVE
		CITY:			PEABODY
		STATE:			MA
		ZIP:			01960
		BUSINESS PHONE:		978-535-7668

	MAIL ADDRESS:	
		STREET 1:		ONE LAKELAND PARK DRIVE
		CITY:			PEABODY
		STATE:			MA
		ZIP:			01960

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Grace David R
		CENTRAL INDEX KEY:			0001302538

	FILING VALUES:
		FORM TYPE:		5
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	000-50924
		FILM NUMBER:		091134434

	MAIL ADDRESS:	
		STREET 1:		BEACON ROOFING SUPPLY, INC.
		STREET 2:		1 LAKELAND PARK DRIVE
		CITY:			PEABODY
		STATE:			MA
		ZIP:			01960
</SEC-HEADER>
<DOCUMENT>
<TYPE>5
<SEQUENCE>1
<FILENAME>edgar.xml
<DESCRIPTION>FORM 5 -
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0303</schemaVersion>

    <documentType>5</documentType>

    <periodOfReport>2009-09-30</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <form3HoldingsReported>0</form3HoldingsReported>

    <form4TransactionsReported>0</form4TransactionsReported>

    <issuer>
        <issuerCik>0001124941</issuerCik>
        <issuerName>BEACON ROOFING SUPPLY INC</issuerName>
        <issuerTradingSymbol>BECN</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001302538</rptOwnerCik>
            <rptOwnerName>Grace David R</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>ONE LAKELAND PARK DRIVE</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>PEABODY</rptOwnerCity>
            <rptOwnerState>MA</rptOwnerState>
            <rptOwnerZipCode>01960</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>0</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>CFO, Treasurer &amp; SVP-Finance</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock, $.01 par value</value>
            </securityTitle>
            <transactionDate>
                <value>2009-09-21</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>5</transactionFormType>
                <transactionCode>G</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>250</value>
                </transactionShares>
                <transactionPricePerShare>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>214014</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock, $.01 par value</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>5128</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>See Note 2</value>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">Reflects a gift by Mr. Grace to The Open Door/Cape Ann Food Pantry, Inc.</footnote>
        <footnote id="F2">These shares are held by Mr. Grace's wife individually and as custodian for their son. Mr. Grace's son owns 4,528 shares and his wife owns 600 shares. Mr. Grace disclaims beneficial ownership of these shares.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>David R. Grace</signatureName>
        <signatureDate>2009-10-23</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
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