JM (Johns Manville) R-49 Unfaced Fiberglass Batt Insulation, 16 in x 48 in, 32 sq ftR 49 Unfaced Fiberglass Batt Insulation JM R 49 unfaced fiberglass batt insulation is designed for wood framed attics, ceilings, and floors to help improve energy efficiency and reduce sound transmission. Pre cut 16 in x 48 in batts fit standard 16 in on center spacing and can be added over existing insulation where no vapor barrier is needed. Key Features: High thermal performance: R 49 fiberglass batts help reduce heat loss and improve overall

R-49 Unfaced Fiberglass Batt Insulation

JM R-49 unfaced fiberglass batt insulation is designed for wood-framed attics, ceilings, and floors to help improve energy efficiency and reduce sound transmission. Pre-cut 16-in x 48-in batts fit standard 16-in on-center spacing and can be added over existing insulation where no vapor barrier is needed.

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Key Features:

• High thermal performance: R-49 fiberglass batts help reduce heat loss and improve overall energy efficiency
• Unfaced design: No vapor barrier—ideal for layering over existing insulation where appropriate
• Sized for standard framing: Pre-cut 16-in x 48-in batts for 16-in on-center joist spacing
• Added comfort: Helps provide sound control in floors/ceilings
• Indoor air quality focused: Formaldehyde-free and GREENGUARD Gold Certified

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Specifications Table:

Specification	Details
Brand	JM
Category	Batt Insulation
R-Value	R-49
Insulation Type	Fiberglass
Faced/Unfaced	Unfaced
Coverage Area (Sq. Feet)	32
Width (Inches)	16
Length (Inches)	48
Thickness (Inches)	13.5
R-Value per Inch	3.63
Maximum R-Value	49
Stud Spacing (Inches)	16
Framing Type	Wood studs
Vapor Retardant	No
Sound Barrier	Yes
Formaldehyde Free	Yes
ENERGY STAR Certified	Yes
GREENGUARD Gold Certified	Yes
Package Type	Multi-pack
Package Count	6
Total Package Quantity	24
Multi-Pack Quantity	4
Bag Dimensions (L x W x D)	16.5 x 20 x 49
Package Weight (lbs.)	26.83
For Use in Attics	Yes
For Use in Ceilings	Yes
For Use in Floors	Yes
For Use in Basements	No
For Use in Crawlspaces	No
For Use in Walls	No
Fits 2 x 4 Walls	No
Fits 2 x 6 Walls	No
For Use in Doors	No
For Use in Duct	No
For Use in Electrical	No
For Use in Garage Doors	No
For Use in Masonry	No
For Use in Plumbing	No
For Use in Vents	No
For Use in Windows	No
CA Residents: Prop 65 Warning(s)	No

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Frequently Asked Questions (FAQ):

Q: Where can I use this insulation?
A: It’s intended for wood-framed attics, ceilings, and floors.

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Q: Does this batt include a vapor barrier?
A: No—this product is unfaced and does not include a vapor retardant.

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Q: Will it fit standard framing?
A: Yes, the batts are 16 in wide and 48 in long for 16-in on-center spacing.

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Q: Can I add it over existing insulation?
A: Yes, unfaced fiberglass batts can be added to existing insulation.

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Q: Is it formaldehyde-free and certified for indoor air quality?
A: Yes—Formaldehyde Free is listed as Yes, and it is GREENGUARD Gold Certified.

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Quiet, cocooning comfort—layered in the bones of your home

Great design is as much about what you feel as what you see—and insulation is the invisible luxury that makes a home serene. These R-49 unfaced fiberglass batts tuck cleanly between joists, elevating comfort with warmth retention and sound-softening ease. Use them to fortify attic and ceiling planes so the rooms below feel calmer, more consistent, and effortlessly livable. It’s the kind of behind-the-scenes upgrade that makes everyday living feel truly elevated.

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Upgrade your attic, ceiling, or floor cavities with JM R-49 batts for a more efficient, quieter home.