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
Save 10%

Shipping Estimate
USA
  • USA
  • CAN

Ships within 48 hours · Estimated delivery Jul 4 - Jul 9

Promo Codes Available:

For Your Every Summer RSVP, with Code: SUMMER15

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

Discover Niche Categories That Outsell

Top-Converting Item to Boost Your Average Order

4.5 ★★★★★
Based on 1330 reviews
Sort
Highest Rating
Newest First
Oldest First
Product Reviews
L
Verified Purchase
Lina
Pawtucket, US
★★★★★ 5
Worthwhile!
Size: Medium/Large, Color: Turkey Day Drumstick - Large
I have a small dog with a really strong bite! Usually have to buy toys that are meant for bigger dogs. This has lasted us for what feels like forever. It does sound very heavy when dropped! My dog loves it though! Would definitely recommend!
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on May 2, 2026
N
Verified Purchase
Natasha M.
Omaha, US
★★★★★ 5
Crazy for her iguana!
Size: Medium/Large, Color: Illana the Iguana - Large, Size: Medium/Large, Color: Illana the Iguana - Large
Instant fav for my girl but looks like I'll be replacing often 🤪 she is a super chewer. She loves the soft vs hard combo on toys. Damage in the pic is within 10 mins. 😬😬😬 excellent quality
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on May 27, 2026
W
Verified Purchase
War317
Natrona Heights, US
★★★★★ 3
Foreign body risk for dinosaur dogs
Size: Medium/Large, Color: Dog Ness Monster - Large, Size: Medium/Large, Color: Dog Ness Monster - Large
My dog Bert had foreign body surgery 10 days ago because he swallowed a piece of a toy, so I was looking for something stronger, like for a tyrannosaurus rex. This toy had good reviews, so I bought it for him. In 25 minutes and he'd chomped a chunk of the blue water part off. Bought the toy around 8am, gave it to him around 8pm, and it was in the trash by 8:30pm. This toy is definitely NOT for super chewer tyrannosaurus rex dogs like Bert. But definitely IS a toy that is pretty sturdy and strong for dogs who don't have the bite force of a dinosaur.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on April 12, 2026
G
Verified Purchase
Gary Hugo
Alexandria, US
★★★★★ 4
Definitely not indestructable
Size: Medium/Large, Color: Dog Ness Monster - Large, Size: Medium/Large, Color: Dog Ness Monster - Large
I have a 1-year-old toy fox terrier (Rocky, pictured). He has been chewing on this toy for seven months now; it is one of his favorites. He has been unable to seriously damage the "ocean" portion of this toy, but as you can see from the provided image, the sea serpent has not faired that well. It is missing its snout and smaller portions of the humps. My guess is that the advertiser images showing much larger dogs with "like new" versions of the toy are just that...NEW AND UNCHEWED. I have not had to clean up bits of this toy from my floor, so I assume Rocky has been swallowing them. My hope is that the yellow material of the serpent is not chemically dangerous when exposed to digestive fluids. Rocky easily destroys plush toys in a matter of days if not hours and, consumed pieces of a small microfiber blanket that he liked to toss around and play tug-of-war with (past tense as he destroyed it and has since been trashed after I began finding feces-stained undigested pieces of it lying around). Since this toy has survived seven months and has remained recognizable, I have to agree it is durable. Just beware, if my small toy fox terrier can damage the toy as pictured, expect your large breed chewer to do similar or worse damage. Also, the toy is very heavy! When Rocky drops it down a flight of stairs, it makes a MAJOR thud at the bottom, and sometimes makes me wonder if it might crack the large tile at the bottom. I cautiously recommend the product. Note the yellow frisbee in Rocky's picture. It is only a few months old and surprisingly has not suffered any chew damage despite substantial abuse. It appears to bend in the wind like a proverbial reed, evading damage by yielding to pressure.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on July 5, 2024
E
Verified Purchase
Elaina rice
Chelsea, US
★★★★★ 5
Dog loves it! For tough chewers for sure
Size: Medium/Large, Color: Dog Ness Monster - Large, Size: Medium/Large, Color: Dog Ness Monster - Large
Dog absolutely loves it, he’s super rough on all of his toys they usually last about 10 minutes bore they are torn to shreds. It’s lasting through his chewing so I’m happy. It’s also super cute.
WAS THIS REVIEW HELPFUL?YesReportShare
Reviewed in the United States on April 9, 2026

recommand products