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JM (Johns Manville) R-38 unfaced fiberglass batts are pre-cut for 16-in on-center wood framing to help improve thermal performance and add sound control in attics, ceilings, and floors. Unfaced construction has no vapor barrier, making it suitable for adding over existing insulation where permitted.
| Specification | Details |
|---|---|
| Brand | JM |
| Category | Batt Insulation |
| Insulation Type | Fiberglass |
| Maximum R-Value | R-38 |
| Faced/Unfaced | Unfaced |
| Width (Inches) | 16 |
| Length (Inches) | 48 |
| Thickness (Inches) | 13 |
| Coverage Area (Sq. Feet) | 42.66 |
| Sound Barrier | Yes |
| Vapor Retardant | No |
| Formaldehyde Free | Yes |
| ENERGY STAR Certified | Yes |
| GREENGUARD Gold Certified | Yes |
| Framing Type | Wood studs |
| Stud Spacing (Inches) | 16 |
| R-Value per Inch | 2.923 |
| For Use in Attics | Yes |
| For Use in Ceilings | Yes |
| For Use in Floors | Yes |
| For Use in Walls | No |
| For Use in Basements | No |
| For Use in Crawlspaces | 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 |
| Fits 2 x 4 Walls | No |
| Fits 2 x 6 Walls | No |
| Will not rot, mildew or deteriorate | Yes (as described) |
| Noncorrosive to pipes, wiring and metal studs | Yes (as described) |
| Package Type | Multi-pack |
| Total Package Quantity | 32 |
| Package Count | 8 |
| Multi-Pack Quantity | 4 |
| Bag Dimensions (L x W x D) | 16.5 x 20 x 50 |
| Package Weight (lbs.) | 22 |
| Warranty | 1-year limited |
| UNSPSC | 11162400 |
Q: Where can I use these batts?
A: Designed for wood-framed attics, ceilings, and floors; not listed for walls, basements, or crawlspaces.
Q: Can I install unfaced insulation over existing insulation?
A: Yes—unfaced batts can be added to existing insulation because they do not include a vapor barrier.
Q: What framing size does it fit?
A: It’s sized for 16-in on-center wood framing and comes in 48-in long batts.
Q: Does it include a vapor retarder?
A: No—this product is unfaced and has no vapor retardant.
Q: Does it help with noise?
A: Yes—this product is listed as having a sound barrier for sound control.
There’s a kind of luxury that isn’t loud—it’s felt in the calm of a perfectly tempered room and the hush that settles over a space. These R-38 unfaced fiberglass batts disappear into the structure, adding warmth, acoustic softness, and an effortless sense of ease overhead in attics and across ceilings and floors. I love the pre-cut, standard-bay sizing—clean lines, minimal fuss, maximum impact. Consider it the invisible foundation for living beautifully: comfort, control, and quiet—always in style.
Upgrade your attic or ceiling with JM R-38 unfaced fiberglass batts for better comfort, quieter spaces, and improved efficiency.
Ships within 48 hours · Estimated delivery Jun 23 - Jun 28
US$40
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