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
Save 10%

Pay in installments of $36.53 with ShopPay, AfterPay and Klarna

Shipping Estimate
USA
  • USA
  • CAN

Ships within 48 hours · Estimated delivery Jul 26 - Jul 31

Promo Codes Available:

For Your Every Summer RSVP, with Code: SUMMER15

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

Discover Niche Categories That Outsell

Top-Converting Item to Boost Your Average Order

4.0 ★★★★★
Based on 16 reviews
Sort
Highest Rating
Newest First
Oldest First
Product Reviews
J
Verified Purchase
Jami
Draper, US
★★★★★ 2
Not the best
Size: 7, Color: Black, Size: 7, Color: Black
They are cute but they have a bit of an odd fit that isn’t great for people with narrow feet. They look too dressy to wear with super casual outfits in my opinion. I think the Ugg golden star sandals are much comfier. If you’re wearing these sandals for a really short time they’d be okay. After wearing them around my house for a little while I decided to return them since they started to hurt my feet.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on June 7, 2026
M
Verified Purchase
Ms. Moon
Waukegan, US
★★★★★ 3
Not for narrow feet, very lightweight.
Size: 7.5, Color: Black
My feet are slightly narrow; these were not adjustable enough to make secure. Otherwise they are cute. The material feels kind of light, these were my first attempt at UGGs so I'm not sure if that's typical or an actual quality issue. Either way, they don't seem very durable but I can't imagine these are meant for roughing it.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on May 8, 2026
S
Verified Purchase
sandra
Massapequa, US
★★★★★ 5
Decepcion
Size: 9.5, Color: Molasses
Excelentes sandalias supercomodas y ligeras quedan muy bien al pie, soy 9 y pedí 9.5 excelente
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on May 28, 2026
P
Verified Purchase
Pamela S. Brown
Lowell, US
★★★★★ 5
Great value
Size: 9.5, Color: Black
I absolutely adore these sandals. They are comfortable and super urban. Worth there value all the way around!
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on March 24, 2026
L
Verified Purchase
Lena Y.
Port Orchard, US
★★★★★ 5
Nice so far.
Size: 6.5, Color: Molasses
Comfy. They were tight the first day across the toes but as I've worn them a couple times they are loosening up. The sole is forming to my foot. These are very much like Doc Martin's from the early 2000s. Not sure about quality since I haven't had them for very long.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on March 27, 2026

recommand products