{"product_id":"jm-johns-manville-r-38c-unfaced-fiberglass-batt-insulation-15-1-2-in-x-48-in-10-1-4-in-thick-41-33-sq-ft","title":"JM (Johns Manville) R-38C Unfaced Fiberglass Batt Insulation – 15-1\/2 in x 48 in (10-1\/4 in Thick), 41.33 sq-ft","description":"\n    \u003ch1\u003eJM R-38C Unfaced Fiberglass Batt Insulation\u003c\/h1\u003e\n    \u003cp\u003e\u003cstrong\u003eJM (Johns Manville) R-38C unfaced fiberglass batt insulation helps reduce heat transfer and improve sound control in wood-framed cavities. Made with long, resilient glass fibers and a formaldehyde-free binder, it’s designed for use in attics, walls, floors, ceilings, basements, and crawlspaces.\u003c\/strong\u003e\u003c\/p\u003e\n    \u003chr\u003e\n    \u003ch2\u003eKey Features:\u003c\/h2\u003e\n    \u003cul\u003e\n        \u003cli\u003e\n\u003cstrong\u003eHigh R-Value Performance:\u003c\/strong\u003e R-38C thermal resistance helps improve comfort and energy efficiency in demanding assemblies.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eFormaldehyde-Free Binder:\u003c\/strong\u003e Designed not to off-gas formaldehyde in the indoor environment.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eUnfaced Batt Design:\u003c\/strong\u003e No kraft facing\/vapor retarder—ideal where a separate vapor control strategy is used or for layering over existing insulation (where allowed).\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eDurable Fiberglass Construction:\u003c\/strong\u003e Inorganic glass fibers resist rot and mildew and won’t corrode pipes, wiring, or metal components.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSound Control Benefits:\u003c\/strong\u003e Helps reduce sound transmission through wall and floor\/ceiling assemblies.\u003c\/li\u003e\n    \u003c\/ul\u003e\n    \n    \u003chr\u003e\n    \u003ch2\u003eSpecifications Table:\u003c\/h2\u003e\n    \u003ctable\u003e\n        \u003cthead\u003e\n            \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\n        \u003c\/thead\u003e\n        \u003ctbody\u003e\n            \u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eBrand\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eJM\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eManufacturer\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eJohns Manville\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eProduct type\/category\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eBatt Insulation\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eMaterial\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eFiberglass\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eFacing\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eUnfaced\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eR-Value\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eR-38C\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eWidth\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e15-1\/2 in\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eLength\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e48 in\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eThickness\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e10-1\/4 in\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eCoverage\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e41.33 sq-ft\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eFor use with\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eWood stud framing\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eApplication\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eNew construction and remodels; walls, floors, ceilings, basements, attics, and crawlspaces\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eFlame spread index\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e\u0026lt;25\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eSmoke developed index\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e\u0026lt;50\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eWater vapor sorption\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003e\u0026lt;5 %\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eStandards\/Certifications\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eASTM C665 Type I; ASTM E136; IBC; Energy Star Certified; Greenguard Gold Certified; Indoor Air Quality Certified; NAIMA 16 CFR Part 460; Recycled Content Certified\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eProduct features\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eFormaldehyde-free; thermally efficient; sound control; durable inorganic glass (won’t rot\/mildew\/deteriorate and is non-corrosive); dimensionally stable (won’t slump\/settle\/break down in normal applications)\u003c\/td\u003e\n\u003c\/tr\u003e\n\u003ctr\u003e\n\u003ctd\u003e\u003cstrong\u003eManufacturer part #\u003c\/strong\u003e\u003c\/td\u003e\n\u003ctd\u003eU1347\u003c\/td\u003e\n\u003c\/tr\u003e\n        \u003c\/tbody\u003e\n    \u003c\/table\u003e\n    \u003chr\u003e\n    \u003ch2\u003eFrequently Asked Questions (FAQ):\u003c\/h2\u003e\n    \n    \u003cp\u003e\u003cstrong\u003eQ: What spaces is this batt insulation designed for?\u003c\/strong\u003e\u003cbr\u003e\n    \u003cstrong\u003eA:\u003c\/strong\u003e It’s intended for new construction or remodels in walls, floors, ceilings, basements, attics, and crawlspaces, and for use with wood stud framing.\u003c\/p\u003e\n    \u003chr\u003e\n    \n    \u003cp\u003e\u003cstrong\u003eQ: What does “unfaced” mean?\u003c\/strong\u003e\u003cbr\u003e\n    \u003cstrong\u003eA:\u003c\/strong\u003e Unfaced batts do not include an attached vapor retarder facing; vapor control (if needed) is handled separately based on the assembly and local code.\u003c\/p\u003e\n    \u003chr\u003e\n    \n    \u003cp\u003e\u003cstrong\u003eQ: What are the batt dimensions and thickness?\u003c\/strong\u003e\u003cbr\u003e\n    \u003cstrong\u003eA:\u003c\/strong\u003e Each batt is 15-1\/2 in wide x 48 in long and 10-1\/4 in thick (R-38C).\u003c\/p\u003e\n    \u003chr\u003e\n    \n    \u003cp\u003e\u003cstrong\u003eQ: Does it help with indoor air quality?\u003c\/strong\u003e\u003cbr\u003e\n    \u003cstrong\u003eA:\u003c\/strong\u003e It’s listed as formaldehyde-free and includes certifications such as GREENGUARD Gold and Indoor Air Quality certifications (per provided product data).\u003c\/p\u003e\n    \u003chr\u003e\n    \n    \u003cp\u003e\u003cstrong\u003eQ: Will it sag or settle over time?\u003c\/strong\u003e\u003cbr\u003e\n    \u003cstrong\u003eA:\u003c\/strong\u003e The bonded glass fibers are described as dimensionally stable and designed not to slump, settle, or break down during normal applications.\u003c\/p\u003e\n    \u003chr\u003e\n    \n    \u003ch2\u003eQuiet Luxury, Hidden in the Walls\u003c\/h2\u003e\n    \u003cp\u003eThe most elevated rooms have a secret: comfort you can’t see, but you feel immediately. This unfaced fiberglass batt brings a soft hush and steady warmth to walls and ceilings, supporting a calmer, more composed interior. I love it for spaces where you want performance without visual intrusion—layer it thoughtfully in attics and framed cavities, then let your finishes take center stage. It’s the kind of behind-the-scenes essential that makes everyday living feel unmistakably luxe.\u003c\/p\u003e\n    \n    \u003chr\u003e\n    \u003cp\u003e\u003cstrong\u003eUpgrade your home’s comfort and quiet with JM R-38C unfaced fiberglass batts designed for high-performance wood-framed spaces.\u003c\/strong\u003e\u003c\/p\u003e\n    \n    \n    ","brand":"JM","offers":[{"title":"Default Title","offer_id":52533929247087,"sku":"31979110513","price":650.64,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0830\/3499\/7051\/files\/unnamed_96042841-938b-46dd-8edd-0d474e245a26.jpg?v=1766980878","url":"https:\/\/superarbor.io\/products\/jm-johns-manville-r-38c-unfaced-fiberglass-batt-insulation-15-1-2-in-x-48-in-10-1-4-in-thick-41-33-sq-ft","provider":"Super Arbor","version":"1.0","type":"link"}