<SEC-DOCUMENT>0001628280-20-013346.txt : 20200904
<SEC-HEADER>0001628280-20-013346.hdr.sgml : 20200904
<ACCEPTANCE-DATETIME>20200904175032
ACCESSION NUMBER:		0001628280-20-013346
CONFORMED SUBMISSION TYPE:	4
PUBLIC DOCUMENT COUNT:		1
CONFORMED PERIOD OF REPORT:	20200903
FILED AS OF DATE:		20200904
DATE AS OF CHANGE:		20200904

REPORTING-OWNER:	

	OWNER DATA:	
		COMPANY CONFORMED NAME:			Bacon Charles A. III
		CENTRAL INDEX KEY:			0001679798

	FILING VALUES:
		FORM TYPE:		4
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-36541
		FILM NUMBER:		201162641

	MAIL ADDRESS:	
		STREET 1:		31-35TH STREET
		CITY:			PITTSBURGH
		STATE:			PA
		ZIP:			15201

ISSUER:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Limbach Holdings, Inc.
		CENTRAL INDEX KEY:			0001606163
		STANDARD INDUSTRIAL CLASSIFICATION:	CONSTRUCTION SPECIAL TRADE CONTRACTORS [1700]
		IRS NUMBER:				000000000
		FISCAL YEAR END:			1231

	BUSINESS ADDRESS:	
		STREET 1:		1251 WATERFRONT PLACE
		STREET 2:		SUITE 201
		CITY:			PITTSBURGH
		STATE:			PA
		ZIP:			15222
		BUSINESS PHONE:		(412) 359-2100

	MAIL ADDRESS:	
		STREET 1:		1251 WATERFRONT PLACE
		STREET 2:		SUITE 201
		CITY:			PITTSBURGH
		STATE:			PA
		ZIP:			15222

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	1347 Capital Corp
		DATE OF NAME CHANGE:	20140422
</SEC-HEADER>
<DOCUMENT>
<TYPE>4
<SEQUENCE>1
<FILENAME>wf-form4_159925621749657.xml
<DESCRIPTION>FORM 4
<TEXT>
<XML>
<?xml version="1.0"?>
<ownershipDocument>

    <schemaVersion>X0306</schemaVersion>

    <documentType>4</documentType>

    <periodOfReport>2020-09-03</periodOfReport>

    <notSubjectToSection16>0</notSubjectToSection16>

    <issuer>
        <issuerCik>0001606163</issuerCik>
        <issuerName>Limbach Holdings, Inc.</issuerName>
        <issuerTradingSymbol>LMB</issuerTradingSymbol>
    </issuer>

    <reportingOwner>
        <reportingOwnerId>
            <rptOwnerCik>0001679798</rptOwnerCik>
            <rptOwnerName>Bacon Charles A. III</rptOwnerName>
        </reportingOwnerId>
        <reportingOwnerAddress>
            <rptOwnerStreet1>1251 WATERFRONT PL, STE 201</rptOwnerStreet1>
            <rptOwnerStreet2></rptOwnerStreet2>
            <rptOwnerCity>PITTSBURGH</rptOwnerCity>
            <rptOwnerState>PA</rptOwnerState>
            <rptOwnerZipCode>15222</rptOwnerZipCode>
            <rptOwnerStateDescription></rptOwnerStateDescription>
        </reportingOwnerAddress>
        <reportingOwnerRelationship>
            <isDirector>1</isDirector>
            <isOfficer>1</isOfficer>
            <isTenPercentOwner>0</isTenPercentOwner>
            <isOther>0</isOther>
            <officerTitle>President and CEO</officerTitle>
            <otherText></otherText>
        </reportingOwnerRelationship>
    </reportingOwner>

    <nonDerivativeTable>
        <nonDerivativeTransaction>
            <securityTitle>
                <value>Common Stock</value>
            </securityTitle>
            <transactionDate>
                <value>2020-09-03</value>
            </transactionDate>
            <transactionCoding>
                <transactionFormType>4</transactionFormType>
                <transactionCode>P</transactionCode>
                <equitySwapInvolved>0</equitySwapInvolved>
            </transactionCoding>
            <transactionAmounts>
                <transactionShares>
                    <value>12000</value>
                </transactionShares>
                <transactionPricePerShare>
                    <value>6.622</value>
                    <footnoteId id="F1"/>
                </transactionPricePerShare>
                <transactionAcquiredDisposedCode>
                    <value>A</value>
                </transactionAcquiredDisposedCode>
            </transactionAmounts>
            <postTransactionAmounts>
                <sharesOwnedFollowingTransaction>
                    <value>397664</value>
                </sharesOwnedFollowingTransaction>
            </postTransactionAmounts>
            <ownershipNature>
                <directOrIndirectOwnership>
                    <value>D</value>
                </directOrIndirectOwnership>
            </ownershipNature>
        </nonDerivativeTransaction>
    </nonDerivativeTable>

    <derivativeTable></derivativeTable>

    <footnotes>
        <footnote id="F1">The price reported in column 4 is a weighted average price. These shares were purchased in multiple transactions at prices ranging from $6.50 to $6.715, inclusive. The reporting person undertakes to provide to Limbach Holdings, Inc. (the &quot;Company&quot;), any security holder of the Company, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the range set forth in this footnote.</footnote>
    </footnotes>

    <remarks></remarks>

    <ownerSignature>
        <signatureName>/s/ Jeremiah G. Garvey, Attorney-in-Fact for Charles A. Bacon III</signatureName>
        <signatureDate>2020-09-04</signatureDate>
    </ownerSignature>
</ownershipDocument>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
