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Internet #205972546

Model #RXCB551525

R-23 ComfortBatt Fire Resistant Stone Wool Insulation Batt 15 in. x 47 in. (12-Bags)

  • Maintains R-Value year after year
  • Fire Resistant & Water Repellent
  • Ease of Installation - Cuts Easily & Friction Fits
  • See More Details

per month* suggested payments with months* financing on this $629.47 purchase*

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Product Overview

ROCKWOOL COMFORTBATT is a semi-rigid stone wool batt insulation for exterior wood and steel stud applications in both new construction and renovations. It features a unique flexible edge designed to compress as the batt is inserted then spring back, expanding the batt against the frame studs to give a complete fill. This flexibility ensures the expected R-value is achieved and maintained. Non-combustible and fire resistant, COMFORTBATT will not develop toxic smoke or promote flame spread, even when exposed directly to a fire. It is also offers water and moisture resistance and excellent sound absorbency. COMFORTBATT is an effective way to improve a home's energy efficiency. It is GREENGUARD Gold Certified and contributes to a healthier indoor environment.
  • Fire resistant due to its high melting temperature of 1177°C (2150°F)
  • Excellent sound absorbency
  • Bag coverage: 39.8 sq. ft.
  • Water and moisture resistant; does not absorb moisture to maintain insulating value
  • Easily cut
  • Does not rot or promote growth of fungi or mildew
  • GreenGuard gold certified for indoor air quality
  • Made from natural rock
  • 12 bags included on a pallet
  • Click here to learn more about Eco Options and Energy Efficiency
  • Buying guide and insulation calculator:

    insulation buying guide
    Insulation calculator button

Info & Guides

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Coverage Area (sq. ft.)
Product Length (ft.)
3.91 ft
Product Thickness (in.)
5.5 in
Product Width (in.)
47 in


Bag Size
48 ft. x 16 in. x 24 in.
Batt/Roll Size
3.91 ft. x 5.5 in. x 47 in.
Compatible Install Surface
Coverage Area per Bag (sq. ft.)
Faced or Unfaced
Insulation Features
Friction Fit
Insulation Location
2x6 Wall,Attic,Basement,Ceiling Insulation,Crawlspace,Floor
Insulation R-Value
Insulation Type
Mineral Wool Insulation
Number of Bags
Pieces Per Bag
Pieces per Pallet
Product Weight (lb.)
Roll or Batt

Warranty / Certifications

Warranty Information

Questions & Answers

Typical questions asked about products:

  • Is the product durable?
  • Is the product easy to use?
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Customer Reviews

  • 4.9
    out of 573 reviews
  • 99% recommend this product
Filter by:
Showing 1-10 of 573 reviews
instant warmth
Solid reliable product that prevents spread of fire, good for exterior wall and easy to install. I immediately felt a temperature difference after installing this! I used this for my walls in the boiler room that has a louvred vent to the outside. Highly recommend.
by dannyB
The best product!
I have replaced all of the old 1955 insulation in my home and i am working on the last room right now.I'm using R14 for 2 x 4 application inside my walls.I am so glad that i'm using Roxul as it has already shown to lower my heating bills and the accoustics changed right away.I don't hear much noise outside anymore.It is so easy to install and it's not itchy,i'm cutting the pieces with a bread knife.Thanks guys for a great product!
by Andreas
Great benefits to this product along with great pricing seems far more Superior than regular fibe...
Great benefits to this product along with great pricing seems far more Superior than regular fiberglass and with waterproof and fireproof rating there is no comparison
by AFT
Purchased to fill the rafters (but also used to fill some gaps along the wall as well), it was in...
Purchased to fill the rafters (but also used to fill some gaps along the wall as well), it was in stock and available at our local store and although not the best value option, the fact it was available without having to order made the little extra spent worth it.
by TheCarpentersWife
This mineral wool product is dense and sized to be pushed between 16" oc 2x6 stud walls. It is v...
This mineral wool product is dense and sized to be pushed between 16" oc 2x6 stud walls. It is very easy to install and far less irritating dust than fiberglass. When installation is completed in any room, there is a noticeable reduction of echo when walking on raw wood floors or with talking. I am thrilled with it also being a fire retardant and water repellent. Cuts easily for outlets, power or water lines, or just odd shaped bays. A relatively expensive product, but anyone can install this insulation so you can certainly save on installation costs.
by larrypoo
This should make regular fiberglass insulation obsolete
I'm remodeling my 1950 mid century modern home one room at a time. I started with the hardest room to heat & cool, knocked out the old plaster & had the room sprayed with rigid & soft foam. The guys rushed the job & left some thin spots and even bare wood showing thru. I wanted to fill voids with Roxul but could not find it anywhere in Oklahoma so I hung the drywall anyway. Since then I've found a dealer 30 miles from me that can order it. I've since used Roxul in my sun room & garage. I like it better than the foam & I can easily install it myself.
by Dogwalker
Better Conformance to Joist Spacing
Fiberglass batts depend on springback to original shape, from large compression in packaging. That springiness then results in buckling if a bit oversize for the space. Rockwool doesn't do this. Lost contact with confining surfaces destroys insulation value.
by Attic Access
I am using this to fill in my cathedral ceilings. The rafters are 2"x8"s and with this R23 battin...
I am using this to fill in my cathedral ceilings. The rafters are 2"x8"s and with this R23 batting (2x6 for 16" centers), I am able to leave an air gap from the eaves to the ridge venting. I was concerned with my rafters having slight bowing here and there might cause problems with the rockwool staying in place with just compressed friction (squeezing it into place). Not a problem. With any gaps less than 14", I shaved some off the batt with a fine-tooth hack saw like cutting a long loaf of bread. Any gaps greater than 15", I simply added those shaved lengths into the squeeze. You will definitely want to wear gloves. The itch and dust is NOT terrible, but long sleeves, goggles (or safety glasses), and a dust mask may be in order. I try not looking straight up (I'm using scaffolding), but still get dust in my eyes on occasion. I've hung most of this without the dust-mask, glasses, and long sleeves because it all makes me sweat. Be sure to shower immediately afterwards or you will be rubbing dust into your eyes and skin. Again, much better than fiberglass on every level. Hoping to finish soon. Good luck on your project.
by Pappy
2 people found this helpful
130 year old church restoration, ideal product
Installing comfort batt insulation in the walls and floor of a 130 year old William Critchlow Harris church/cottage upgrade. As this structure is a 'balloon' design, fire concern was paramount. Simple installation even with so many cuts, and huge long term benefits. Ideal application for your product.
by Michael
I am happy with this product.
I like it when i get asked what i'm putting into my walls.I let friends know that this product is safe to handle and not itchy.I'm using a bread knife to cut pieces to fit.I've got peace of mind knowing it's not going to grow mold,it's fire resistant,easy to install and i won't hear as much outside noise in my home.Right now i am installing this product and i am 3/4 completed.
by Andreas
Showing 1-10 of 573 reviews