{"product_id":"gmc-15-asphalt-felt-underlayment-4-square-roll","title":"GMC 15# Asphalt Felt Underlayment, 4 Square Roll","description":"\u003ch1\u003eGMC 15# Asphalt Felt Underlayment, 4 Square Roll\u003c\/h1\u003e\u003chr\u003e\u003cp\u003e\u003cstrong\u003eGMC 15# felt underlayment is a traditional asphalt-saturated organic felt used beneath shingle, tile and metal roofing. Each sell unit is one roll covering 4 squares (400 sq. ft. nominal). It is available in a standard grade and an ASTM D4869-compliant grade, and pairs with any primary roofing membrane system.\u003c\/strong\u003e\u003c\/p\u003e\u003chr\u003e\u003ch2\u003eKey Features:\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eASTM-compliant option:\u003c\/strong\u003e An ASTM D4869 version is offered for jobs specifying that standard.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e4-square roll:\u003c\/strong\u003e Each roll covers 4 squares of roof area.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTwo grades:\u003c\/strong\u003e Offered in both STD and ASTM D4869 variants.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eTraditional felt:\u003c\/strong\u003e Classic 15# asphalt-saturated felt for steep-slope roofs.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWide compatibility:\u003c\/strong\u003e Works under common shingle, tile and metal roof coverings.\u003c\/li\u003e\n\u003c\/ul\u003e\u003chr\u003e\u003ch2\u003eSpecifications Table:\u003c\/h2\u003e\u003ctable\u003e\n\u003cthead\u003e\u003ctr\u003e\n\u003cth\u003e\u003cstrong\u003eSpecification\u003c\/strong\u003e\u003c\/th\u003e\n\u003cth\u003e\u003cstrong\u003eDetails\u003c\/strong\u003e\u003c\/th\u003e\n\u003c\/tr\u003e\u003c\/thead\u003e\n\u003ctbody\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eBrand\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eGMC\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eSell unit\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e1 roll, 4 square\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eProduct line\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eGMC Felt 15#\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eAvailable sizes\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e4 Square\/Roll (both variants)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eMaterial\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eAsphalt-saturated felt underlayment\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eCoverage per unit\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e4 squares (400 sq. ft.) per roll\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eApprovals\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eASTM D4869 (D4869 variant)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eIntended use\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eRoofing underlayment beneath shingles, tile or metal\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003c\/tbody\u003e\n\u003c\/table\u003e\u003chr\u003e\u003ch2\u003eCoverage \u0026amp; How Much You Need:\u003c\/h2\u003e\u003cp\u003eOne roll covers 4 squares, or 400 sq. ft. nominal. Divide total roof area by 400 to estimate rolls needed, then add laps and waste per fastening and overlap requirements of the roof covering.\u003c\/p\u003e\u003ch2\u003eFit and Compatibility:\u003c\/h2\u003e\u003cp\u003eDesigned for use under shingle, clay tile, concrete tile and metal roofing as the water-shedding layer over the deck. Choice between the STD and ASTM D4869 grades depends on the job specification.\u003c\/p\u003e\u003chr\u003e\u003ch2\u003eFrequently Asked Questions (FAQ):\u003c\/h2\u003e\u003cp\u003e\u003cstrong\u003eQ: What is included in each roll?\u003c\/strong\u003e\u003cbr\u003e\u003cstrong\u003eA:\u003c\/strong\u003e Each sell unit is one 4-square roll of 15# asphalt felt.\u003c\/p\u003e\u003chr\u003e\u003cp\u003e\u003cstrong\u003eQ: Which grade should I order?\u003c\/strong\u003e\u003cbr\u003e\u003cstrong\u003eA:\u003c\/strong\u003e Order the ASTM D4869 variant when a specification or code calls for that standard; the STD grade is the conventional 15# felt.\u003c\/p\u003e\u003chr\u003e\u003cp\u003e\u003cstrong\u003eQ: How many rolls do I need?\u003c\/strong\u003e\u003cbr\u003e\u003cstrong\u003eA:\u003c\/strong\u003e Divide your roof area by 400 sq. ft. per roll and add extra for laps and waste.\u003c\/p\u003e\u003chr\u003e\u003cp\u003e\u003cstrong\u003eQ: How is it installed?\u003c\/strong\u003e\u003cbr\u003e\u003cstrong\u003eA:\u003c\/strong\u003e Roll it out over the roof deck and fasten per the roof covering manufacturer's requirements before installing the finish roof.\u003c\/p\u003e\u003chr\u003e\u003cp\u003e\u003cstrong\u003eQ: Is a weight or UPC published?\u003c\/strong\u003e\u003cbr\u003e\u003cstrong\u003eA:\u003c\/strong\u003e No roll weight or UPC is published in the available sources.\u003c\/p\u003e\u003chr\u003e\u003ch2\u003eExpert Verdict — Reviewed by the SuperArbor Pro Desk\u003c\/h2\u003e\u003cp\u003eAs a roofing-supply expert, I recommend the ASTM D4869 roll whenever the spec sheet names that standard, since inspectors may ask for it. Felt remains a cost-effective underlayment for steep-slope asphalt shingle jobs; keep rolls dry until install and lap per the shingle exposure in your local code. Order extra rolls for hips, valleys and starter laps.\u003c\/p\u003e\u003cp\u003e\u003cem\u003eInstall underlayment on dry decks and use fall protection when working on roofs, following OSHA and local requirements.\u003c\/em\u003e\u003c\/p\u003e\u003chr\u003e\u003cp\u003e\u003cstrong\u003eOrder GMC 15# felt underlayment rolls today for dependable coverage under your next roof.\u003c\/strong\u003e\u003c\/p\u003e","brand":"GMC","offers":[{"title":"4 Square\/Roll ASTM D4869","offer_id":53524576207215,"sku":"GMC15FD4869","price":36.0,"currency_code":"USD","in_stock":true},{"title":"4 Square\/Roll STD","offer_id":53524576239983,"sku":"GMC15F","price":26.5,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0830\/3499\/7051\/files\/ProductImage_GMC15FD4869.jpg?v=1790284653","url":"https:\/\/superarbor.io\/products\/gmc-15-asphalt-felt-underlayment-4-square-roll","provider":"Super Arbor","version":"1.0","type":"link"}