Johns Manville (JM) R-38 Unfaced Fiberglass Batt Insulation, 16 in x 48 in, 42.66 sq ft
SKU: 65548730391

Johns Manville (JM) R-38 Unfaced Fiberglass Batt Insulation, 16 in x 48 in, 42.66 sq ft

Sale price$134.24 Regular price$149.16
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Description

Johns Manville (JM) R-38 Unfaced Fiberglass Batt Insulation, 16 in x 48 in, 42.66 sq ftR 38 Unfaced Fiberglass Batt Insulation (16 in x 48 in) 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. Key Features: High R Value Performance: R 38 fiberglass batts help reduce heat transfer for

R-38 Unfaced Fiberglass Batt Insulation (16 in x 48 in)

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.


Key Features:

  • High R-Value Performance: R-38 fiberglass batts help reduce heat transfer for improved comfort and energy efficiency.
  • Unfaced for Flexible Use: No vapor barrier, so it can be added to existing insulation where appropriate.
  • Sized for Standard Framing: Pre-cut 48-in length and 16-in width fits 16-in on-center wood framing bays.
  • Sound Control Added: Built-in sound barrier helps reduce noise transmission between spaces.
  • Durable, Moisture-Resistant Material: Won’t rot, mildew, or deteriorate and is noncorrosive to pipes, wiring, and metal components.

Specifications Table:

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

Frequently Asked Questions (FAQ):

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.


Quiet, cocooning comfort—layered into your home’s architecture

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.

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: 65548730391

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Bethalyn
Grantham, US
★★★★★ 5
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Color: Bule 0, Size: For Larege Dogs
Our big boy is rough with his toys and always seems to disintegrate his toys in seconds. I had seen this with hoping this will be the toy he doesn’t destroy. On day 2 now with the toy and he’s obsessed, even feel asleep with the toy in his mouth and still in one piece. Highly recommended for tough chewers.
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Reviewed in the United States on May 25, 2026
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Nani
Charlottesville, US
★★★★★ 3
Good but not for my dog
Color: A Red, Size: For Larege Dogs
Dog loves it but already falling apart. Can't seem to find a truly safe dog toy that won't come apart with my aggressive chewer. Had to toss it before pieces got ingested. But great toy in the begining. Just not safe for pit/staff type dog that destroy and chew.
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Reviewed in the United States on May 25, 2026
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Mayberry mommy
Battle Creek, US
★★★★★ 5
Put your aggressive Chewer dog to the test!
Color: A Red, Size: For Larege Dogs
A very tough toy to stand up to my aggressive chewer lab! It's a great value! The squeak is not annoying, and she's got to clamp down hard on it. It's a nice throw toy! It bounces once or twice but it still brings out the pup in our Dog! Not too small a nice size for a Lab or retriever
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Reviewed in the United States on June 7, 2026
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Mo
Draper, US
★★★★★ 5
A Hardy Toy for Chewers
Color: Bule Octopus, Size: For Larege Dogs, Color: Bule Octopus, Size: For Larege Dogs
I must say I was very surprised with the durability of this toy. We've had it for 3 days and not one puncture hole. My rescue is a destroy chewer that doesn't care for Hardy chew toys unless it squeaks. While the squeaker isn't the best, he still loves it. We put peanut butter in the grooves for him and he goes to town. Will purchase again should he ever destroys it, worth the price!
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Reviewed in the United States on May 8, 2026
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Jeffrey Brown
Cuba, US
★★★★★ 5
Durable toy for a great price! Will buy again.
Color: A Red, Size: For Larege Dogs, Color: A Red, Size: For Larege Dogs
Great toy, heavy, good size, and durable for active chewers. My two dogs like to play tug a war a lot and this toy has held up fantastically! Afterwards they tend to chew toys to pieces but this one has stood the test of time so far. Great buy!
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