Johns Manville R-38 Attic Unfaced Fiberglass Batt Insulation, 63.33-sq ft Coverage (23.75-in W x 48-in L) - U1348S
SKU: 34372709744

Johns Manville R-38 Attic Unfaced Fiberglass Batt Insulation, 63.33-sq ft Coverage (23.75-in W x 48-in L) - U1348S

Sale price$131.50 Regular price$146.11
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Description

Johns Manville R-38 Attic Unfaced Fiberglass Batt Insulation, 63.33-sq ft Coverage (23.75-in W x 48-in L) - U1348SR 38 Unfaced Fiberglass Batt Insulation for Attics Formaledehyde free fiberglass batts deliver R 38 thermal performance for attics and cathedral ceilings. Pre cut 48 in lengths fit 24 in on center framing and provide 63. 33 sq ft of coverage per pack. Key Features: High R Value Performance: R 38 insulation boosts energy efficiency and comfort Unfaced Design: No vapor barrierideal for adding over existing insulation Pre Cut Convenience: 48 in batts

R-38 Unfaced Fiberglass Batt Insulation for Attics

Formaledehyde-free fiberglass batts deliver R-38 thermal performance for attics and cathedral ceilings. Pre-cut 48-in lengths fit 24-in on-center framing and provide 63.33 sq ft of coverage per pack.


Key Features:

  • High R-Value Performance: R-38 insulation boosts energy efficiency and comfort
  • Unfaced Design: No vapor barrier—ideal for adding over existing insulation
  • Pre-Cut Convenience: 48-in batts sized for 23.75-in width cavities with 24-in stud spacing
  • Durable Fiberglass: Will not rot, mildew, or corrode pipes, wiring, or metal studs
  • Low Emissions Certifications: GREENGUARD Gold and SCS Recycled Content certified

Specifications Table:

Specification Details
Coverage Area (Sq. Feet) 63.33
Length (Inches) 48
Width (Inches) 23.75
Thickness (Inches) 12
Faced/Unfaced Unfaced
Framing Type Wood studs
Insulation Type Fiberglass
Maximum R-Value 38
R-Value per Inch 3.1667
Stud Spacing (Inches) 24
For Use in Attics Yes
For Use in Ceilings Yes
For Use in Walls No
For Use in Floors 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
Formaldehyde Free Yes
Sound Barrier Yes
Vapor Retardant No
ENERGY STAR Certified Yes
GREENGUARD Gold Certified Yes
Warranty 1-year limited
Bag Dimensions (L x W x D) 24.3 x 20 x 50
Package Weight (lbs.) 45.68
Package Type Multi-pack
Package Count 8
Multi-Pack Quantity 4
Total Package Quantity 32
UNSPSC 11162400

Frequently Asked Questions (FAQ):

Q: How much area does one pack cover?
A: Each pack provides 63.33 square feet of coverage.


Q: Can I install this over existing insulation?
A: Yes, the unfaced batts can be laid over existing attic insulation where a vapor barrier is not needed.


Q: What framing spacing is this sized for?
A: These batts are designed for 24-in on-center framing with a 23.75-in cavity width.


Q: Is the product formaldehyde-free?
A: Yes, it is formaldehyde-free and GREENGUARD Gold certified for indoor air quality.


Q: Where can it be used?
A: Primarily for attics and cathedral ceilings; not intended for walls or crawlspaces.


Quiet, Cozy Attics with Effortless Elegance

This R-38 batt brings a serene hush and steady comfort to upper levels, wrapping your home in a clean, minimalist layer. The slim profile is tailored for cathedral ceilings, creating a refined envelope without bulk. Pair it with soft, natural finishes—think pale woods and matte paints—to amplify its calm energy efficiency. Consider it a foundational luxury: invisible, indispensable, and beautifully effective.


Upgrade your attic with R-38 performance and start saving on energy costs today.

Shipping Notes
  • Free Standard Shipping on $100+ Orders to the USA.
  • Except Preorder products are shipped in 48 hours.
  • Delivery to the USA:
  1. Standard Shipping : 3-10 business days
  • If time is of the essence, please consider selecting expedited delivery for faster service.
Exchange/Return Notes
  • We offer a 30-day return/exchange service after receiving.
  • Final sale items are not eligible for returns or exchanges.
  • To process your return/exchange, please contact us at [email protected]
  • Please click here for more details>>> Return & Exchange Policy
SKU: 34372709744

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Y. B.
Lowell, US
★★★★★ 3
check measurements
Color: Black, Size: Wheel-176''
smaller than expected
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on May 14, 2025
A
Verified Purchase
Amanda
Louisville, US
★★★★★ 1
Do not buy this!!
Color: Black, Size: Wheel-132''
The holes to assemble it together were in the wrong places and it was welded together, so you can’t move it around. I’m not able to use this.
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Reviewed in the United States on February 9, 2025
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Verified Purchase
Stephanie Moore
Massapequa, US
★★★★★ 5
Nice
Color: Black, Size: Wheel-132''
Very nice. They fulfilled the purpose.
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Reviewed in the United States on June 17, 2025
A
Verified Purchase
Amazon Customer
Boise, US
★★★★★ 5
Good Product
Size: 3 Panel-102'', Color: Beige
I got these dividers for outdoor use for some privacy from neighbors. They arrived quickly and were easy to set up. They look good, and though the legs don’t offer stability against any amount of wind—which I expected as it wasn’t advertised for outdoor use—all it took was placing a cinder block on the feet to hold it up right. Coverage is good, it’s easy to fold and move as needed, and it’s light weight. All in all a decent product. I will caution the purchase of “used like-new,” as both of the dividers I ordered were previously returned items, and one came missing a cap, instructions were not included, and the poles were all mixed up and not properly labeled. If I had not ordered a second divider (which did include the instructions) I would have had a much harder time figuring out which pieces were which and how to put them together.
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Reviewed in the United States on May 30, 2025
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Verified Purchase
julie h.
Port Orchard, US
★★★★★ 5
So versatile! Perfect solution for dividing a room.
Size: 4 Panel-88'', Color: Grey, Size: 4 Panel-88'', Color: Grey
Perfect solution for my space. My office has to double as the hangout room for the kids and I wanted something that would block off my computer so it is left alone. This space allows me to close off my computer as much or as little as I want. It is lightweight yet has sturdy feet. This is important so that if it gets bumped it won’t topple over. The price was great and the build time wasn’t too bad! I would recommend two people for set up. I went with the grey panels and I think I’ll end up hanging some twinkle lights at some point. Great purchase!
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Reviewed in the United States on October 9, 2025

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