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

    <schemaVersion>X0303</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2008-10-09</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0000107294</issuerCik>
        <issuerName>WILLIAMS INDUSTRIES INC</issuerName>
        <issuerTradingSymbol>wmsi.pk</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001055499</rptOwnerCik>
            <rptOwnerName>WILLIAMS FRANK E JR</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>2789-B HARTLAND ROAD</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>FALLS CHURCH</rptOwnerCity>
            <rptOwnerState>VA</rptOwnerState>
            <rptOwnerZipCode>22043</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>0</isOfficer>
            <isTenPercentOwner>1</isTenPercentOwner>
            <isOther>0</isOther>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2008-10-09</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>J</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
                <footnoteId id="F6"/>
            </transactionCoding>
            <transactionTimeliness>
                <value></value>
            </transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>0</value>
                    <footnoteId id="F6"/>
                </transactionShares>
                <transactionPricePerShare>
                    <value>0</value>
                    <footnoteId id="F6"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>D</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>651792</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
        <nonDerivativeHolding>
            <securityTitle>
                <value>common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>826456</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>by Williams Family LP</value>
                    <footnoteId id="F1"/>
                    <footnoteId id="F2"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>338300</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Williams Enterprises of Georgia, Inc.</value>
                    <footnoteId id="F3"/>
                    <footnoteId id="F4"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>176879</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>by spouse</value>
                    <footnoteId id="F5"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>13000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>as Trustee for minor grandchildren</value>
                    <footnoteId id="F5"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
        <nonDerivativeHolding>
            <securityTitle>
                <value>common Stock</value>
            </securityTitle>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>54100</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>I</value>
                </directOrIndirectOwnership>
                <natureOfOwnership>
                    <value>By Williams Family Foundation</value>
                    <footnoteId id="F5"/>
                </natureOfOwnership>
            </ownershipNature>
        </nonDerivativeHolding>
    </nonDerivativeTable>

    <derivativeTable>
        <derivativeHolding>
            <securityTitle>
                <value>option</value>
            </securityTitle>
            <conversionOrExercisePrice>
                <value>4.1</value>
            </conversionOrExercisePrice>
            <exerciseDate>
                <value>2005-01-20</value>
            </exerciseDate>
            <expirationDate>
                <value>2010-01-19</value>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>6000</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>6000</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeHolding>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">As previously reported, 150,000 shares owned by the Williams Family LP are subject to a pledge in favor of a banking institution to secure indebtedness of the Williams Family LP. This was reported on the advice of counsel because the pledge of the shares grants dispositive power to the lender, who may dispose of the shares without further consent of the owner in the event of default on the underlying indebtedness.</footnote>
        <footnote id="F2">Except as noted in Footnote #1, I have sole dispositive power over these shares, and I am also a beneficial owner with my sons Frank E. Williams, III and H. Arthur Williams. These shares are duplicative of shares reported for my sons.</footnote>
        <footnote id="F3">As previously reported, 338,300 shares owned by Williams Enterprises of Georgia, Inc. are subject to a pledge in favor of a banking institution to secure indebtedness of Williams Enterprises of Georgia, Inc. This was reported on the advice of counsel because the pledge of the shares grants dispositive power to the lender, who may dispose of the shares without further consent of the owner in the event of default on the underlying indebtedness</footnote>
        <footnote id="F4">Except as noted in Footnote #3, I have dispositive power over these shares, and I am also a beneficial owner with my sons Frank E. Williams, III and H. Arthur Williams. These shares are duplicative of shares reported for my sons.</footnote>
        <footnote id="F5">I disclaim beneficial ownership of these share</footnote>
        <footnote id="F6">This is to report the pledge of 350,000 shares owned by me to a banking institution to secure indebtedness of myself.  This is reported on advice of counsel because the pledge of the shares grants dispositive power to the lender who may dispose of the shares without further consent of the owner in the event of default on the underlying  indebtedness.</footnote>
    </footnotes>

    <remarks>1. As previously reported, 150,000 shares owned by the Williams Family LP are subject to a pledge in favor of a banking institution to secure indebtedness of the Williams Family LP. This was reported on the advice of counsel because the pledge of the shares grants dispositive power to the lender, who may dispose of the shares without further consent of the owner in the event of default on the underlying indebtedness.
2. Except as noted in Footnote #1, I have sole dispositive power over these shares, and I am also a beneficial owner with my sons Frank E. Williams, III and H. Arthur Williams. These shares are duplicative of shares reported for my sons.
3. As previously reported, 338,300 shares owned by Williams Enterprises of Georgia, Inc. are subject to a pledge in favor of a banking institution to secure indebtedness of Williams Enterprises of Georgia, Inc. This was reported on the advice of counsel because the pledge of the shares grants dispositive power to the lender, who may dispose of the shares without further consent of the owner in the event of default on the underlying indebtedness
4. Except as noted in Footnote #3, I have dispositive power over these shares, and I am also a beneficial owner with my sons Frank E. Williams, III and H. Arthur Williams. These shares are duplicative of shares reported for my sons.
5. I disclaim beneficial ownership of these share</remarks>

    <ownerSignature>
        <signatureName>Frank E. Williams, Jr.</signatureName>
        <signatureDate>2008-10-10</signatureDate>
    </ownerSignature>
</ownershipDocument>
