Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.
Click here to Find a Contractor in your area.


I've been in many houses with Cotton insulation. Most were built in the 40's and 50's. All the cotton was compressed to nearly nothing. What a surprise to find this stuff in ceiling joists in the attic when pulling down a piece of pressboard..... yeh baby.

Big Plus... NO ITCH!!!!



  • Skippy_3
    Skippy_3 Member Posts: 3

    I'm looking for some help, has any one here been told that 2.75" thick cotton insulation will fluff out to 5.25" thick and provide an r-19? Has any one been around the cotton insulation?
  • hr
    hr Member Posts: 6,106
    I've seen some shreded blue jean

    insulation used on a couple "green" jobs recently.

    Unless it is listed to a known accepted standard, claims of R-value can be somewhat questionable, to be polite.

    Fiberglass batts generally have all the listings printed on the wrappers and at the websites.

    hot rod

    To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"
  • Just Curious,

    What was that old stuff they had in the 60`s called "rock wool", it was white, or was it called "mineral fiber", was there a diff between that and cotton?

  • Gimpy Greg_4
    Gimpy Greg_4 Member Posts: 2
    Mineral Wool

    The mineral wool I am familiar with is not
    a plant fiber like cotton. It was made from blast furnace
    slag, hot liquid limestone that was allowed to cool after being dumped on the ground. It was then scooped up,looking
    and feeling light like a gray lava rock and screened. In this form it was used for road and sidewalk bed and anti-
    skid material in the winter. It was also reheated to a
    liquid and spun like cotton candy to make mineral fiber.
    It was sold in 30 lb. bags to be used as "dump in"
    insulation and 740 lb. bales which were used by insulation
    contractors to blow in walls and attics. It could also
    be used to make batts, essentially doing anything fiberglass could do. Also was used to make ceiling tiles.
    I also believe certain natural minerals can be used to make insulation wih the same process. Having used it to insulate several attics, I can say it is less uncomfortable to work with than fiberglass but still not
    "itchless". I believe it is still manufactured but still
    not as popular as fiberglass. If it is white or pink or yellow it is probably fiberglass, if it is gray it is probably rock or mineral wool. Be it fiberglass or mineral wool, to you it will handle and perform about the same.
    I will let those with a vested interest debate the finer
    details of cost vs. performance. Thus endeth the sermon
  • Thanks Greg

    GREAT explanation, I appreciate-it.

This discussion has been closed.