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  1. #1
    Join Date
    Aug 2007
    Posts
    1

    Default Insulate Floors Over Crawl Space? What about walls?

    Hi, I bought a 1950s red-brick house in Alambama, and am wondering two things. First, should I insulate under the floorboards (in the crawl space). I put down some plastic (4mm) on the ground already, but it's very hot and humid here. WOuld I need plastic above or below the insulation too? Second, how do I know if I have enough insulation in my walls, and how would I go about insulating them if I don't want to rip out the sheetrock.

    Thanks
    Jamesm

  2. #2
    Join Date
    Jun 2007
    Location
    Erie, PA
    Posts
    51

    Default Re: Insulate Floors Over Crawl Space? What about walls?

    Insulating the floor will help, the plastic would go directly on the ground. I would recommend 2lb Closed Cell Spray Foam Insulation. This product will never sag or settle over time. The only true way to find out how much insulation is in your walls, is to open a small hole somewhere, like inside a closet. Their are many different ways you can insulate if you don't have any insulation at all.

  3. #3
    Join Date
    Aug 2007
    Posts
    2

    Default Re: Insulate Floors Over Crawl Space? What about walls?

    I have a similar need for insulation in an enclosed porch with a crawl. The porch is attached to the house and crawl is next to the basement (but with small openings). I want to use the porch year round but need to insulate it from below (floor joists). Any suggestions?

  4. #4
    Join Date
    Jun 2007
    Location
    Erie, PA
    Posts
    51

    Default Re: Insulate Floors Over Crawl Space? What about walls?

    2lb closed cell spray foam insulation is what you need to use.
    2" minimum thickness as this will have a vapor barrier built in. If your entrance is too small for a human to enter, try to enlarge it so a guy/gal can access the area

  5. #5
    Join Date
    Sep 2007
    Posts
    1

    Default Re: Insulate Floors Over Crawl Space? What about walls?

    I have a similar insulating crawlspace problem. I'm building a two room cabin in the woods in upstate NY (cold in the winter). The cabin is up on piers. I plan to use fiberglass batts between the floor joists. To keep small rodents from burrowing in the insulation and to act as a vapor shield, I plan to staple a 6mil sheet of plastic to the bottom of the joists. Is this a good idea? Will it create a mold prone situation and will it keep out critters? I once had a house on the tip of Long Island and the fiberglass insulation installed by a previous owner and unprotected by plastic sheeting had become water saturated. What should I do?

    Alan

  6. #6
    Join Date
    Jun 2007
    Location
    Erie, PA
    Posts
    51

    Default Re: Insulate Floors Over Crawl Space? What about walls?

    I would install a 2lb closed cell foam at a minimum average thickness of 2". This will give you your vapor barrier, and will out perform any other insulation on the market. The foam will not absorb water, insects can not burrow through it (ants, silverfish, spiders, etc) The foam will never shrink, sag, settle, or lose its R-value over time or temp.

  7. #7
    Join Date
    Dec 2008
    Posts
    5

    Default Re: Insulate Floors Over Crawl Space? What about walls?

    Quote Originally Posted by Bay Harbor Insulation View Post
    I would install a 2lb closed cell foam at a minimum average thickness of 2". This will give you your vapor barrier, and will out perform any other insulation on the market. The foam will not absorb water, insects can not burrow through it (ants, silverfish, spiders, etc) The foam will never shrink, sag, settle, or lose its R-value over time or temp.
    what is the r value of 2" of this product?

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