JM (Johns Manville)
JM (Johns Manville) R-49 Unfaced Fiberglass Batt Insulation, 16 in x 48 in, 32 sq ft
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SKU 31979072460
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Details
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.
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
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 |
Frequently Asked Questions (FAQ):
Q: Where can I use this insulation?
A: It’s intended for wood-framed attics, ceilings, and floors.
Q: Does this batt include a vapor barrier?
A: No—this product is unfaced and does not include a vapor retardant.
Q: Will it fit standard framing?
A: Yes, the batts are 16 in wide and 48 in long for 16-in on-center spacing.
Q: Can I add it over existing insulation?
A: Yes, unfaced fiberglass batts can be added to existing insulation.
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.
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.
Upgrade your attic, ceiling, or floor cavities with JM R-49 batts for a more efficient, quieter home.
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