<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0202</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2004-06-01</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000103973</issuerCik>
        <issuerName>VULCAN MATERIALS CO</issuerName>
        <issuerTradingSymbol>VMC</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001188412</rptOwnerCik>
            <rptOwnerName>CARROLL PHILIP J JR</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>RIVER OAKS BANK BUILDING</rptOwnerStreet1>
            <rptOwnerStreet2>2001 KIRBY DRIVE, SUITE 910</rptOwnerStreet2>
            <rptOwnerCity>HOUSTON</rptOwnerCity>
            <rptOwnerState>TX</rptOwnerState>
            <rptOwnerZipCode>77019</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle></officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock (Restricted Stock Units)</value>
            </securityTitle>
            <transactionDate>
                <value>2004-06-01</value>
            </transactionDate>
            <deemedExecutionDate></deemedExecutionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F1"/>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>1000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>46.039</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>5191.369</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>Common Stock (Deferred Stock Units)</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>280.523</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">Annual stock grant made to the reporting person under the Vulcan Materials Company Restricted Stock Plan for Nonemployee Directors.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>Amy M. Tucker</signatureName>
        <signatureDate>2004-06-03</signatureDate>
    </ownerSignature>
</ownershipDocument>
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X0202
4
2004-06-01
0
0000103973
VULCAN MATERIALS CO
VMC
0001188412
CARROLL PHILIP J JR
RIVER OAKS BANK BUILDING
2001 KIRBY DRIVE, SUITE 910
HOUSTON
TX
77019
1
0
0
0
Common Stock (Restricted Stock Units)
2004-06-01
4
A
0
1000
46.039
A
5191.369
D
Common Stock (Deferred Stock Units)
280.523
D
Annual stock grant made to the reporting person under the Vulcan Materials Company Restricted Stock Plan for Nonemployee Directors.
Amy M. Tucker
2004-06-03