JM R-21 Unfaced Fiberglass Batt Insulation – 15 in x 105 in, 76.56 sq ft (2x6 Walls)

Regular price $86.83

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R-21 Unfaced Fiberglass Wall Batts

JM R-21 unfaced fiberglass batt insulation is designed to improve thermal performance and help reduce unwanted sound transfer in interior wall cavities. Pre-cut batts fit standard 2x6 wood-stud walls and can be added to existing insulation where no vapor retarder is desired.


Key Features:

  • Thermal + Sound Control: R-21 performance helps manage heat flow while also supporting sound control in wall cavities
  • Unfaced Design: No built-in vapor retarder—ideal for adding to existing insulation or assemblies that require separate vapor control
  • Sized for Standard Framing: Pre-cut for 2x6 wood-stud walls with 16-in on-center spacing (15-in wide batts)
  • Easy Press-Fit Installation: Designed to press in place between studs for straightforward DIY or pro installs
  • Durable Fiberglass: Will not rot, mildew, or deteriorate; noncorrosive to pipes, wiring, and metal components

Specifications Table:

Specification Details
Insulation Type Fiberglass
R-Value R-21
R-Value per Inch 3.8182
Width 15 in
Length 105 in
Thickness 5.5 in
Coverage Area 76.56 sq ft
Faced/Unfaced Unfaced
Vapor Retardant No
Sound Barrier Yes
Stud Spacing 16 in
Fits Wall Framing 2x6
Framing Type Wood studs
Formaldehyde Free Yes
ENERGY STAR Certified Yes
GREENGUARD Gold Certified Yes
For Use in Walls Yes
For Use in Basements Yes
For Use in Attics No
For Use in Ceilings No
For Use in Floors No
Package Weight 32.73 lb
Package Count 7
Total Package Quantity 28
Multi-Pack Quantity 4
Package Type Multi-pack
Bag Dimensions (L x W x D) 20 x 20 x 50
Warranty 1-year limited

Frequently Asked Questions (FAQ):

Q: What wall cavities does this insulation fit?
A: It’s sized for 2x6 walls with 16-inch on-center stud spacing (15-inch wide batts).


Q: Does this batt include a vapor barrier?
A: No—this is unfaced insulation and does not include a vapor retarder.


Q: Where can it be used?
A: It’s intended for wall applications and is noted for use in basements; it is not listed for attics, ceilings, or floors on the provided spec sheet.


Q: How much area does one package cover?
A: Coverage is listed as 76.56 sq ft per package.


Q: Is it certified for indoor air quality?
A: It’s listed as GREENGUARD Gold Certified and formaldehyde-free in the provided specifications.


Quiet Luxury, Hidden in the Walls

The most elevated spaces are never just about what you see—they’re about how the room feels. These unfaced R-21 fiberglass batts create a calmer, more temperature-stable backdrop, softening noise and supporting energy-smart comfort without changing your visual palette. Designed to slip cleanly into standard 2x6 wall cavities, they’re a discreet upgrade that lets your finishes—and your life—take center stage. It’s the kind of behind-the-scenes essential that makes everyday living feel undeniably luxe.


Upgrade your 2x6 walls with JM R-21 unfaced fiberglass batts for comfort-forward energy savings and better sound control.

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Subject to Approval & Availability
All orders are reviewed before fulfillment. You are not charged until your order is approved and ready to ship — and you may cancel at any time before that at no cost.

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