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Internet #

202090820

Model #

RXCB351525

Store SKU #

974419

R-15 Comfortbatt 3-1/2 in. x 15 in. x 47 in. Fire Resistant Stone Wool Insulation Batt (59.7 sq. ft.)

Covers 59.7 sq.ft. ($1.31 /sq.ft.)
$78.47
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  • Easy to install with a friction fit and a consistent R-Value
  • Compression pack, one bag includes 12 pieces and covers 59.7 sqft
  • Sound reduction and fire resistance designed for exterior walls
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Product Details

ROCKWOOL Comfortbatt is a semi-rigid stone wool thermal batt insulation for exterior wood and steel stud applications. It features a unique flexible edge that allows for easy installation and helps prevent over compression to maintain its R-value. Non-combustible and fire resistant, Comfortbatt will not develop toxic smoke or promote flame spread, even when exposed directly to a fire. It 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.
  • Excellent thermal performance providing a high R-value per inch
  • Non-combustible and fire resistant, stone wool works to contain a fire and prevent its spread
  • 3-1/2 in. x 15-1/4 in. batt sizing is designed for 2x4 wood framed construction spaced 16 in. on center
  • Comfortbatt applications include: exterior walls between studs, basement walls, crawlspaces, attics and cathedral ceilings and exposed floors
  • Stone wool provides excellent noise reduction and sound absorption to help you create quieter, more productive environments
  • Water resistant, stone wool does not rot or promote the growth of mildew, fungi or mold
  • Lightweight and easy to install, cut using a serrated knife and compression fit into place
  • Friction fit batts conform to normal variations in stud centers caused by distortion or warping
  • GREENGUARD gold certified for indoor air quality
  • Click here to learn more about Eco Options and Energy Efficiency
  • Buying guide and insulation calculator:

    insulation buying guide
    Insulation calculator button
  • Return Policy
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Specifications

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Questions & Answers

102Questions
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Q:Why does description say r-15 but the picture shows r30 (r-30)?
by|Apr 4, 2023
1 Answer
Answer This Question

A:  The description is specifically for part RXCB351525. The picture is not showing the correct product. This product is R15

by|Apr 4, 2023
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    Q:Can R-15 be used for the rafters or is it too thin?
    by|Apr 3, 2023
    1 Answer
    Answer This Question

    A:  R-Value ROCKWOOL product is meant for any stud/joist cavity that would benefit from thermal protection. Your local building codes will dictate what R-Value is required in your walls and you can use a single piece of ROCKWOOL to achieve this R-Value or you can stack the ROCKWOOL pieces on top of one another to add their R-Value together. Eg. Two batts of R15 insulation will provide R30 resistance in your wall. Hopefully this answers your question and we wish you the best on your project.

    by|Apr 3, 2023
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      Q:do you need to put moisture barrier on if it used in a unconditional space?
      by|Mar 2, 2023
      2 Answers
      Answer This Question

      A:  Good Morning Chris. The use of a vapor retarder is dependent on the climate zone and local building codes. Can you email us direct with your location and confirm the application. Thanks techservice@rockwool.com Note that If the application is for an interior partition wall or between floors, then a vapor retarder should not be a requirement.

      by|May 13, 2023
        1 found this answer helpful

        A:  Below is a link to the installation guide. https://images.thdstatic.com/catalog/pdfImages/2b/2b0eaaa6-5d03-481a-afd2-541ca0ef82e2.pdf Mike

        by|Mar 3, 2023
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        Q:How many linear feet of joist gap will each bundle cover?
        by|Jan 28, 2023
        2 Answers
        Answer This Question

        A:  The R15 bundle holds 12 batts of insulation. Each batt is 47 inches in length which works out to 47 linear feet in coverage

        by|Jan 30, 2023

          A:  This material covers 59.7 square feet. You can calculate linear feet by multiplying by 12 and dividing by width.

          by|Apr 21, 2023
            1 found this answer helpful
            Showing 1-4 of 102
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            Customer Reviews

            4.9 out of 5
            (640)
            • 4.9
              out of 640 reviews
            • 99% recommend this product
            Filter by:
            Showing 1-10 of 640 reviews
            Very Good Product
            I installed about 650 square feet of insulation in my attic and was plesantly suprised with the ease of installation of the ROCKWOOL Comfortbatt (R-15) material. I placed Comfortbatts in between the ceil joists (full dimesional 2x4 on 16 centers). I then placed rolled R-30 Fiberglass, perpendicular to the joist direction. The Comfortbatt did not generate the dust and fibers that I found were generated with the fiberglass batt installation. The ROCKWOOL material came in easy to manage packaged bundles and when opened the material expanded very nicely. It cut easily with the bread knife as desribed. I did find inconsistencies in the cohesiveness of the Comfortbatts. Some were very cohesive and I could grab them with my hand and easily slide them into place between the ceiling joists, while other Comfortbatts would pull apart when I tried to grab the batt and slide it between the joists. Overall, I do like the general density and noise reduction of the Comfortbatts. I used the hybrid ROCKWOOL/fiberglass system to help reduce the overall cost, with the fiberglass having a higher R-value and costing about $300 less than the ROCKWOOL for the same area.
            by
              Comfort Batt
              Once I started demolition I noticed the old insulation and it was wasn’t up to standard. I used the ROCKWOOL Comfort Batt insulation to bring the kitchen up to the building code. Easy to use and the home already feels better.
              by
                Best Insulation
                I have used Rockwood in my exterior walls, interior walls, floor joists and most recently in the walls of my campervan. It is easy to work with, excellent for sound proofing, provides better fire protection and does not saturate with moisture. Best Insulation product for people who want the best Insulation with few trade offs.
                by
                  Basement rim joist insulation
                  Worked on removing and replacing the orig. fiberglass batt insulation in the basement. I chose the Rockwool Comfortbatt R15 batt since it appear to be a better product than replacing with new fiberglass batts. I think the Rockwool product was sightly more expansive, but I found it easy to work with. We'll see how good are the energy savings over time.
                  by
                    Rockwool rocks!
                    First time using Rockwool in our renovated home. As soon as we put it in the house was quieter and instantly warmer. We are now at the drywall stage and are only using two small electric portable heaters and the house is T-shirt warm! I can imagine how warm it will be once we turn the furnace on and how much money we will save in heating bills! The Rockwool Comfortbatt product is so easy to use and went up so quickly. We had one whole floor done in two days with just two of us doing the work. Will only use Rockwool from now on. We have recommended the comfortbatt and Rockwool comfort board to our daughter and husband as they will be doing a renovation to their home soon. So pleased with this company and products. Thank you!
                    by
                      Rockwool rocks!
                      First time using Rockwool in our renovated home. As soon as we put it in the house was quieter and instantly warmer. We are now at the drywall stage and are only using two small electric portable heaters and the house is T-shirt warm! I can imagine how warm it will be once we turn the furnace on and how much money we will save in heating bills! The Rockwool Comfortbatt product is so easy to use and went up so quickly. We had one whole floor done in two days with just two of us doing the work. Will only use Rockwool from now on. We have recommended the comfortbatt and Rockwool comfort board to our daughter and husband as they will be doing a renovation to their home soon. So pleased with this company and products. Thank you!
                      by
                        Great Material
                        Five star material here. Easy to cut and install, just select a good vapor barrier I chose Intello Membrane and done. I do like benefit of this material not being able to burn. And if it get wet it will dry out and will still do the job it was intended to do. And no itchy arms while installing it, perfect !
                        by
                          Great Material
                          Five star material here. Easy to cut and install, just select a good vapor barrier I chose Intello Membrane and done. I do like benefit of this material not being able to burn. And if it get wet it will dry out and will still do the job it was intended to do. And no itchy arms while installing it, perfect !
                          by
                            Easy to customize
                            Said goodbye to pink crap insulation and hello to lovely rockwool. Had major problems with squirrels in old log cabin unfinished basement ceiling. Once we cleared out the old insulation (riddled with poop and nests), we crossed our fingers that this new insulation would be inhospitable. The week after installation, they messed with one small section, which we pushed back into place with a garden hoe. I had to repeat this a few days later, but the insulation wasn’t destroyed just pushed out of place. Since then, no issues (about 2 months as of this writing). There are many wires and pipes (for geothermal heating) in that basement ceiling, so installation went slowly in some sections. But the stuff cuts so easily that it’s not hard to customize. Just always “measure twice, cut once” as my father used to say. I’m not a contractor, not even close. Just a homeowner capable of the most basic home maintenence. I found rockwool comfortbatt easy to work with and was very proud that we could do this ourselves!
                            by
                              Inspector was very impressed
                              DIY installed comfort batt in my 2 story 1200sq foot guest house workshop on top of 2 inch closed cell spray foam Extremely easy to work with. Love the tidy appearance and so did the inspector.
                              by
                                Showing 1-10 of 640 reviews

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