✨ New Arrivals Just Dropped!Explore
HomeStore

Johns Manville (JM) R-49 Unfaced Fiberglass Batt Insulation 24 in x 48 in, 48 sq ft (U4924)

Johns Manville (JM) R-49 Unfaced Fiberglass Batt Insulation 24 in x 48 in, 48 sq ft (U4924)

R-49 Unfaced Fiberglass Batt Insulation (24 in x 48 in)

Johns Manville (JM) unfaced fiberglass batt insulation delivers high thermal performance (R-49) for energy-efficient comfort in residential framing cavities. Made with durable, formaldehyde-free bonded glass fibers, it also helps reduce sound transmission for quieter interiors.


Key Features:

  • High R-Value Performance: R-49 thermal resistance helps slow heat transfer for improved comfort and efficiency.
  • Formaldehyde-Free Fiberglass: Designed to avoid off-gassing formaldehyde in indoor environments.
  • Sound Dampening: Helps reduce noise transmission through walls, floors, and ceiling assemblies.
  • Durable, Non-Decay Material: Inorganic glass fibers resist rot, mildew, and deterioration and are non-corrosive to pipes and wiring.
  • Stable Fit in Cavities: Dimensionally stable batts resist slumping and settling in typical applications.

Please check the Product Data Sheet Here


Specifications Table:

Specification Details
R-Value R-49
Insulation Type Fiberglass batt
Facing Unfaced
Width 24 in
Length 48 in
Thickness 13-1/2 in
Coverage Area 48 sq ft
For Use With Wood stud framing
Application For new construction and remodels; walls, floors, ceilings, basements, attics, and crawlspaces
Flame Spread Index <25
Smoke Developed Index <50
Temperature Rating 850 deg F
Water Vapor Sorption <5 %
Standards/Certifications ASTM C665 Type I; ASTM E136; IBC; Energy Star Certified; Greenguard Gold Certified; Indoor Air Quality Certified; NAIMA 16 CFR Part 460; Recycled Content Certified
Manufacturer Johns Manville
Manufacturer Part # U4924
Pieces Per Package 6

Frequently Asked Questions (FAQ):

Q: Is this insulation faced or unfaced?
A: It is unfaced fiberglass batt insulation.


Q: What stud framing is it intended for?
A: It is listed for use with wood stud framing.


Q: Where can it be used in a home?
A: It’s listed for new construction and remodels in walls, floors, ceilings, basements, attics, and crawlspaces.


Q: What are the batt dimensions and thickness?
A: Each batt is 24 in wide x 48 in long and approximately 13-1/2 in thick.


Q: Does it meet common fire/smoke performance criteria?
A: It is listed with flame spread index <25 and smoke developed index <50.


Quiet Luxury, Layered Into the Bones of the Home

Think of this as the invisible couture of a well-designed space—an uncompromising layer that refines comfort without asking for attention. The unfaced fiberglass batt brings a high R-value warmth and a hush that makes rooms feel instantly more intentional. Use it to elevate bedrooms, media rooms, or any wall assembly where serenity is the ultimate finish. It’s the kind of behind-the-scenes essential that makes luxury living feel effortless, every day.


Upgrade your build with JM R-49 unfaced batts for high-performance thermal comfort and quieter rooms.

$51.77

Original: $172.57

-70%
Johns Manville (JM) R-49 Unfaced Fiberglass Batt Insulation 24 in x 48 in, 48 sq ft (U4924)

$172.57

$51.77

Product Information

Shipping & Returns

Description

R-49 Unfaced Fiberglass Batt Insulation (24 in x 48 in)

Johns Manville (JM) unfaced fiberglass batt insulation delivers high thermal performance (R-49) for energy-efficient comfort in residential framing cavities. Made with durable, formaldehyde-free bonded glass fibers, it also helps reduce sound transmission for quieter interiors.


Key Features:

  • High R-Value Performance: R-49 thermal resistance helps slow heat transfer for improved comfort and efficiency.
  • Formaldehyde-Free Fiberglass: Designed to avoid off-gassing formaldehyde in indoor environments.
  • Sound Dampening: Helps reduce noise transmission through walls, floors, and ceiling assemblies.
  • Durable, Non-Decay Material: Inorganic glass fibers resist rot, mildew, and deterioration and are non-corrosive to pipes and wiring.
  • Stable Fit in Cavities: Dimensionally stable batts resist slumping and settling in typical applications.

Please check the Product Data Sheet Here


Specifications Table:

Specification Details
R-Value R-49
Insulation Type Fiberglass batt
Facing Unfaced
Width 24 in
Length 48 in
Thickness 13-1/2 in
Coverage Area 48 sq ft
For Use With Wood stud framing
Application For new construction and remodels; walls, floors, ceilings, basements, attics, and crawlspaces
Flame Spread Index <25
Smoke Developed Index <50
Temperature Rating 850 deg F
Water Vapor Sorption <5 %
Standards/Certifications ASTM C665 Type I; ASTM E136; IBC; Energy Star Certified; Greenguard Gold Certified; Indoor Air Quality Certified; NAIMA 16 CFR Part 460; Recycled Content Certified
Manufacturer Johns Manville
Manufacturer Part # U4924
Pieces Per Package 6

Frequently Asked Questions (FAQ):

Q: Is this insulation faced or unfaced?
A: It is unfaced fiberglass batt insulation.


Q: What stud framing is it intended for?
A: It is listed for use with wood stud framing.


Q: Where can it be used in a home?
A: It’s listed for new construction and remodels in walls, floors, ceilings, basements, attics, and crawlspaces.


Q: What are the batt dimensions and thickness?
A: Each batt is 24 in wide x 48 in long and approximately 13-1/2 in thick.


Q: Does it meet common fire/smoke performance criteria?
A: It is listed with flame spread index <25 and smoke developed index <50.


Quiet Luxury, Layered Into the Bones of the Home

Think of this as the invisible couture of a well-designed space—an uncompromising layer that refines comfort without asking for attention. The unfaced fiberglass batt brings a high R-value warmth and a hush that makes rooms feel instantly more intentional. Use it to elevate bedrooms, media rooms, or any wall assembly where serenity is the ultimate finish. It’s the kind of behind-the-scenes essential that makes luxury living feel effortless, every day.


Upgrade your build with JM R-49 unfaced batts for high-performance thermal comfort and quieter rooms.

Johns Manville (JM) R-49 Unfaced Fiberglass Batt Insulation 24 in x 48 in, 48 sq ft (U4924) | Super Arbor