<SEC-DOCUMENT>0000007431-26-000013.txt : 20260226
<SEC-HEADER>0000007431-26-000013.hdr.sgml : 20260226
<ACCEPTANCE-DATETIME>20260226170019
ACCESSION NUMBER:		0000007431-26-000013
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20260225
FILED AS OF DATE:		20260226
DATE AS OF CHANGE:		20260226

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Grizzle Victor
		CENTRAL INDEX KEY:			0001509566
		ORGANIZATION NAME:           	

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-02116
		FILM NUMBER:		26690283

	MAIL ADDRESS:	
		STREET 1:		2500 COLUMBIA AVE
		CITY:			LANCASTER
		STATE:			PA
		ZIP:			17603

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			ARMSTRONG WORLD INDUSTRIES INC
		CENTRAL INDEX KEY:			0000007431
		STANDARD INDUSTRIAL CLASSIFICATION:	PLASTICS PRODUCTS, NEC [3089]
		ORGANIZATION NAME:           	08 Industrial Applications and Services
		EIN:				230366390
		STATE OF INCORPORATION:			PA
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		2500 COLUMBIA AVE
		CITY:			LANCASTER
		STATE:			PA
		ZIP:			17603
		BUSINESS PHONE:		7173970611

	MAIL ADDRESS:	
		STREET 1:		2500 COLUMBIA AVE
		CITY:			LANCASTER
		STATE:			PA
		ZIP:			17603

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	ARMSTRONG CORK CO
		DATE OF NAME CHANGE:	19800611
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>form4.xml
<DESCRIPTION>PRIMARY DOCUMENT
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0508</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2026-02-25</periodOfReport>

    <issuer>
        <issuerCik>0000007431</issuerCik>
        <issuerName>ARMSTRONG WORLD INDUSTRIES INC</issuerName>
        <issuerTradingSymbol>AWI</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001509566</rptOwnerCik>
            <rptOwnerName>Grizzle Victor</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>C/O ARMSTRONG WORLD INDUSTRIES, INC.</rptOwnerStreet1>
            <rptOwnerStreet2>2500 COLUMBIA AVENUE</rptOwnerStreet2>
            <rptOwnerCity>LANCASTER</rptOwnerCity>
            <rptOwnerState>PA</rptOwnerState>
            <rptOwnerZipCode>17603</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <officerTitle>CEO</officerTitle>
        </reportingOwnerRelationship>
    </reportingOwner>

    <aff10b5One>0</aff10b5One>

    <derivativeTable>
        <derivativeTransaction>
            <securityTitle>
                <value>Restricted Stock Units</value>
                <footnoteId id="F1"/>
            </securityTitle>
            <conversionOrExercisePrice>
                <footnoteId id="F1"/>
            </conversionOrExercisePrice>
            <transactionDate>
                <value>2026-02-25</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>A</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionTimeliness></transactionTimeliness>
            <transactionAmounts>
                <transactionShares>
                    <value>6272</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>172.21</value>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <exerciseDate>
                <footnoteId id="F2"/>
            </exerciseDate>
            <expirationDate>
                <footnoteId id="F2"/>
            </expirationDate>
            <underlyingSecurity>
                <underlyingSecurityTitle>
                    <value>Common Stock</value>
                </underlyingSecurityTitle>
                <underlyingSecurityShares>
                    <value>6272</value>
                </underlyingSecurityShares>
            </underlyingSecurity>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>6272</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </derivativeTransaction>
    </derivativeTable>

    <footnotes>
        <footnote id="F1">Each restricted stock unit represents a contingent right to receive one share of the Issuer's common stock under the Issuer's 2022 Equity and Cash Incentive Plan.</footnote>
        <footnote id="F2">The restricted stock units were granted to the Reporting Person on February 25, 2026 and will vest in full on the earlier of (i) February 25, 2029 (contingent upon the Reporting Person's employment with the Issuer on the scheduled vesting date, except as provided for under the Issuer's 2022 Equity and Cash Incentive Plan) and (ii) the Reporting Person's retirement, provided such retirement occurs on or after December 25, 2026, subject to the terms of the Issuer's 2022 Equity and Cash Incentive Plan.</footnote>
    </footnotes>

    <ownerSignature>
        <signatureName>/s/ Alan M. Kidd, Attorney-in-fact</signatureName>
        <signatureDate>2026-02-26</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
