{"product_id":"densdeck-prime-1-4-in-primed-roof-board-4-ft-x-8-ft-sheet-cover-board","title":"DensDeck Prime 1\/4 in. Primed Roof Board 4 ft. x 8 ft. Sheet (Cover Board)","description":"\u003ch2\u003ePrimed gypsum roof cover board sheet\u003c\/h2\u003e \u003cp\u003e\u003cstrong\u003eDensDeck Prime is a primed gypsum roof board designed to provide a durable, high-performance cover board surface for commercial roofing assemblies. It features a fiberglass mat facer and high-density gypsum core to help improve membrane bond strength while supporting fire and moisture resistance requirements in many systems.\u003c\/strong\u003e\u003c\/p\u003e \u003chr\u003e \u003ch3\u003eKey Features:\u003c\/h3\u003e \u003cul\u003e \u003cli\u003e \u003cstrong\u003eEnhanced Adhesion Surface:\u003c\/strong\u003e Coated fiberglass facer is designed to provide improved compatibility and performance with roofing adhesives in fully adhered systems.\u003c\/li\u003e \u003cli\u003e \u003cstrong\u003eFire-Resistant Cover Board:\u003c\/strong\u003e Noncombustible gypsum roof board with 0\/0 flame spread and smoke developed when tested per ASTM E84; referenced as FM Class 1\/UL Class A performance for assemblies.\u003c\/li\u003e \u003cli\u003e \u003cstrong\u003eMoisture-Resistant Performance:\u003c\/strong\u003e Designed for water resistance with up to 5% water absorption by weight and 1-gram nominal surface water absorption on both sides.\u003c\/li\u003e \u003cli\u003e \u003cstrong\u003eSystem Versatility:\u003c\/strong\u003e Created for mechanically fastened, adhered, and partially adhered roofing systems.\u003c\/li\u003e \u003cli\u003e \u003cstrong\u003eDurable Protection Layer:\u003c\/strong\u003e Helps defend roof assemblies from punctures, wind, and jobsite\/foot-traffic wear.\u003c\/li\u003e \u003c\/ul\u003e \u003chr\u003e \u003ch3\u003eSpecifications Table:\u003c\/h3\u003e \u003ctable\u003e \u003cthead\u003e \u003ctr\u003e \u003cth\u003e\u003cstrong\u003eSpecification\u003c\/strong\u003e\u003c\/th\u003e \u003cth\u003e\u003cstrong\u003eDetails\u003c\/strong\u003e\u003c\/th\u003e \u003c\/tr\u003e \u003c\/thead\u003e \u003ctbody\u003e \u003ctr\u003e \u003ctd\u003e\u003cstrong\u003eSheet size\u003c\/strong\u003e\u003c\/td\u003e \u003ctd\u003e4 ft x 8 ft\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd\u003e\u003cstrong\u003eThickness (nominal)\u003c\/strong\u003e\u003c\/td\u003e \u003ctd\u003e1\/4 in (6.4 mm) ± 1\/16 in (1.6 mm)\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd\u003e\u003cstrong\u003eWidth tolerance\u003c\/strong\u003e\u003c\/td\u003e \u003ctd\u003e4 ft (1219 mm) ± 1\/8 in (3 mm)\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd\u003e\u003cstrong\u003eR-value\u003c\/strong\u003e\u003c\/td\u003e \u003ctd\u003e0.28 (°F•ft²•hr\/BTU)\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd\u003e\u003cstrong\u003eFlame spread \u0026amp; smoke developed\u003c\/strong\u003e\u003c\/td\u003e \u003ctd\u003e0\/0 (ASTM E84)\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd\u003e\u003cstrong\u003eMold resistance\u003c\/strong\u003e\u003c\/td\u003e \u003ctd\u003e10\/10\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd\u003e\u003cstrong\u003ePermeance\u003c\/strong\u003e\u003c\/td\u003e \u003ctd\u003e\u0026gt;30 perms (\u0026gt;1710 ng\/Pa•s•m²)\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd\u003e\u003cstrong\u003eWater absorption (max)\u003c\/strong\u003e\u003c\/td\u003e \u003ctd\u003e5%\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd\u003e\u003cstrong\u003eSurface water absorption (nominal)\u003c\/strong\u003e\u003c\/td\u003e \u003ctd\u003e1.0 gram (both sides)\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd\u003e\u003cstrong\u003eCompressive strength (nominal)\u003c\/strong\u003e\u003c\/td\u003e \u003ctd\u003e900 psi\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd\u003e\u003cstrong\u003eFlexural strength, parallel (min)\u003c\/strong\u003e\u003c\/td\u003e \u003ctd\u003e≥40 lbf (178 N)\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd\u003e\u003cstrong\u003eBending radius\u003c\/strong\u003e\u003c\/td\u003e \u003ctd\u003e4 ft (1219 mm)\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd\u003e\u003cstrong\u003eLinear variation with change in temperature\u003c\/strong\u003e\u003c\/td\u003e \u003ctd\u003e8.5 x 10^-6 in\/in\/°F (15.3 x 10^-6 mm\/mm\/°C)\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd\u003e\u003cstrong\u003eLinear variation with change in moisture\u003c\/strong\u003e\u003c\/td\u003e \u003ctd\u003e6.25 x 10^-6\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd\u003e\u003cstrong\u003eFlute spanability\u003c\/strong\u003e\u003c\/td\u003e \u003ctd\u003e2-5\/8 in (66.7 mm)\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd\u003e\u003cstrong\u003eStandards \/ test methods referenced\u003c\/strong\u003e\u003c\/td\u003e \u003ctd\u003eASTM C1177; ASTM C473; ASTM E84; ASTM E96; ASTM C518; ASTM E661\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd\u003e\u003cstrong\u003eBoard type\u003c\/strong\u003e\u003c\/td\u003e \u003ctd\u003ePrimed gypsum roof board \/ cover board\u003c\/td\u003e \u003c\/tr\u003e \u003ctr\u003e \u003ctd\u003e\u003cstrong\u003eConstruction\u003c\/strong\u003e\u003c\/td\u003e \u003ctd\u003eFiberglass mat facer with high-density gypsum core\u003c\/td\u003e \u003c\/tr\u003e \u003c\/tbody\u003e \u003c\/table\u003e \u003chr\u003e \u003ch3\u003eFrequently Asked Questions (FAQ):\u003c\/h3\u003e \u003cp\u003e\u003cstrong\u003eQ: What size and thickness is this board?\u003c\/strong\u003e\u003cbr\u003e \u003cstrong\u003eA:\u003c\/strong\u003e This product is a 4 ft. x 8 ft. sheet with a nominal 1\/4 in. thickness.\u003c\/p\u003e \u003chr\u003e \u003cp\u003e\u003cstrong\u003eQ: What types of roofing systems is it used with?\u003c\/strong\u003e\u003cbr\u003e \u003cstrong\u003eA:\u003c\/strong\u003e It is intended for mechanically fastened, adhered, and partially adhered roofing systems as a cover board and bonding surface.\u003c\/p\u003e \u003chr\u003e \u003cp\u003e\u003cstrong\u003eQ: Is this board moisture resistant?\u003c\/strong\u003e\u003cbr\u003e \u003cstrong\u003eA:\u003c\/strong\u003e Yes—published performance notes up to 5% water absorption by weight and 1-gram nominal surface water absorption on both sides of the board.\u003c\/p\u003e \u003chr\u003e \u003cp\u003e\u003cstrong\u003eQ: Does it have fire performance ratings?\u003c\/strong\u003e\u003cbr\u003e \u003cstrong\u003eA:\u003c\/strong\u003e Published data notes 0\/0 flame spread\/smoke developed (ASTM E84) and references FM Class 1 and UL Class A performance in assemblies.\u003c\/p\u003e \u003chr\u003e \u003cp\u003e\u003cstrong\u003eQ: Is it compatible with roofing adhesives?\u003c\/strong\u003e\u003cbr\u003e \u003cstrong\u003eA:\u003c\/strong\u003e Yes—the enhanced\/coated fiberglass facer is described as improving compatibility and performance with roofing adhesives, especially in fully adhered systems.\u003c\/p\u003e \u003chr\u003e \u003ch3\u003eA sleek, high-performance foundation for the roofline\u003c\/h3\u003e \u003cp\u003eThere’s a quiet luxury in materials that do the hard work beautifully—DensDeck Prime brings a crisp, primed surface and a refined, fiberglass-faced finish that elevates what’s beneath the membrane. Its high-density gypsum core is engineered for resilience, helping the roof assembly stand up to moisture, fire demands, and the wear of real-world conditions. Pair it with fully adhered systems when you want that confident, continuous bond and a cleaner build sequence. It’s the kind of unseen layer that makes the entire structure feel impeccably considered.\u003c\/p\u003e \u003chr\u003e \u003cp\u003e\u003cstrong\u003eChoose DensDeck Prime 1\/4 in. 4x8 to add a durable, moisture- and fire-conscious cover board layer that helps your roofing system perform longer.\u003c\/strong\u003e\u003c\/p\u003e","brand":"GMC_Traffic","offers":[{"title":"Default Title","offer_id":55154291540259,"sku":"gmc16-01090","price":15.25,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0980\/8730\/5507\/files\/cf617f4b6704affc.jpg?v=1779819083","url":"https:\/\/a2ztoyshop.us.com\/products\/densdeck-prime-1-4-in-primed-roof-board-4-ft-x-8-ft-sheet-cover-board","provider":"Grandview Hobbies","version":"1.0","type":"link"}