{"product_id":"gmc-30-felt-underlayment-2-squares-per-roll-astm-d4869","title":"GMC 30# Felt Underlayment, 2 Squares per Roll, ASTM D4869","description":"\u003ch1\u003eGMC 30# Felt Underlayment, 2 Squares per Roll, ASTM D4869\u003c\/h1\u003e\u003chr\u003e\u003cp\u003e\u003cstrong\u003eGMC 30# Felt Underlayment is asphalt-saturated roofing felt meeting ASTM D4869, supplied in rolls covering 2 squares (200 sq. ft.). It installs over roof decking beneath shingles as a secondary water-shedding layer. One sell unit is one roll.\u003c\/strong\u003e\u003c\/p\u003e\u003chr\u003e\u003ch2\u003eKey Features:\u003c\/h2\u003e\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eASTM D4869 compliant:\u003c\/strong\u003e Manufactured to meet ASTM D4869 for asphalt-saturated felt underlayment.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e30# weight class:\u003c\/strong\u003e Heavy 30# felt offers a robust secondary layer under shingles.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e2 squares per roll:\u003c\/strong\u003e Each roll covers 200 sq. ft. of roof deck.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eWide compatibility:\u003c\/strong\u003e Works beneath standard asphalt shingle roof systems.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eRoll format:\u003c\/strong\u003e Supplied in rolls for fast, efficient deck coverage.\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, 2 squares (ASTM D4869)\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 30#\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 (No. 30)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eNominal size\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e2 squares per roll (200 sq. ft.)\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\u003e2 squares (200 sq. ft.) per roll\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eStandard\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eASTM D4869\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eIntended use\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eResidential roofing underlayment beneath shingles\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eAssembly\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eUnrolled and fastened over roof deck, shingle courses lapped per code and manufacturer instructions\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 2 squares, or 200 sq. ft. of roof deck. Divide the total roof area in squares by 2 and add rolls for lap and waste allowance.\u003c\/p\u003e\u003ch2\u003eFit and Compatibility:\u003c\/h2\u003e\u003cp\u003eDesigned as an underlayment beneath asphalt shingle roofing on residential slopes. Starter strip, shingles, ridge caps and fasteners are sold separately; verify slope and lap requirements with the shingle manufacturer's installation instructions.\u003c\/p\u003e\u003chr\u003e\u003ch2\u003eFrequently Asked Questions (FAQ):\u003c\/h2\u003e\u003cp\u003e\u003cstrong\u003eQ: What is included?\u003c\/strong\u003e\u003cbr\u003e\u003cstrong\u003eA:\u003c\/strong\u003e One roll of GMC 30# felt underlayment covering 2 squares, meeting ASTM D4869.\u003c\/p\u003e\u003chr\u003e\u003cp\u003e\u003cstrong\u003eQ: How much does one roll cover?\u003c\/strong\u003e\u003cbr\u003e\u003cstrong\u003eA:\u003c\/strong\u003e Each roll covers 2 squares, or 200 sq. ft., before lap allowances.\u003c\/p\u003e\u003chr\u003e\u003cp\u003e\u003cstrong\u003eQ: What standard does it meet?\u003c\/strong\u003e\u003cbr\u003e\u003cstrong\u003eA:\u003c\/strong\u003e It meets ASTM D4869 for asphalt-saturated felt underlayment.\u003c\/p\u003e\u003chr\u003e\u003cp\u003e\u003cstrong\u003eQ: Where is it used?\u003c\/strong\u003e\u003cbr\u003e\u003cstrong\u003eA:\u003c\/strong\u003e As underlayment over roof decking beneath asphalt shingles in residential roofing.\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 deck, lap courses per code and shingle manufacturer instructions, and fasten with cap nails or caps.\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 in squares by two, then add extra for laps, valleys and waste.\u003c\/p\u003e\u003chr\u003e\u003ch2\u003eExpert Verdict — Reviewed by the SuperArbor Pro Desk\u003c\/h2\u003e\u003cp\u003eThirty-pound felt is a dependable, code-recognized underlayment choice for pitched shingle roofs and a good backup layer in storms. Keep rolls dry and flat before installation, and do not leave felt exposed to weather longer than the shingle manufacturer allows. On low slopes or in high-wind regions, check whether the shingle system calls for a synthetic underlayment or double-felt coverage instead.\u003c\/p\u003e\u003cp\u003e\u003cem\u003eFelt underlayment is slippery, especially when wet or dusty; wear soft-soled shoes with good grip, use roof anchors on steep slopes, and keep the deck surface clean while working.\u003c\/em\u003e\u003c\/p\u003e\u003chr\u003e\u003cp\u003e\u003cstrong\u003eOrder GMC 30# Felt Underlayment rolls meeting ASTM D4869 for your next shingle roof.\u003c\/strong\u003e\u003c\/p\u003e","brand":"GMC","offers":[{"title":"Default Title","offer_id":67583403295087,"sku":"GMC30FD4869","price":36.5,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0830\/3499\/7051\/files\/ProductImage_GMC30FD4869.jpg?v=1790407083","url":"https:\/\/superarbor.io\/products\/gmc-30-felt-underlayment-2-squares-per-roll-astm-d4869","provider":"Super Arbor","version":"1.0","type":"link"}