Insulating a floor HELP?

Discussion in 'Homesteading Questions' started by sue currin, Oct 14, 2006.

  1. sue currin

    sue currin Well-Known Member

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    I can't get under the closed-in floor I built, I put down a sub floor of ship-lap. And I want to put hard wood over that. Do I put tar paper over that, then blue foam board, then wood? or what? No way to put insulation in the underside. Help? Thanks
     
  2. omnicat

    omnicat Well-Known Member

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    I'm no help - but want to add to possible answers - I can get under my floors - there's a crawl space. What would anyone suggest for insulating the underside? My kitchen floor is cold cold cold in the winter. There's a little grate opening in the side of the foundation (ground level - then three cinder-block levels up to the floor of the house). We put a bale of straw there - but it's still a very cold floor.

    (no insulation in the walls, either - but I've been told we want to attach rigid exterior insulation (exulation?) before re-stuccoing the outside. Expensive, and a few years down the trail for us)
     

  3. Highground

    Highground Well-Known Member

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    Sue, why can't you get under there? If it's got a crawl space and you didn't build an entryway, add one in a closet. If it's on slab, I'm no help.

    Omnicat, I helped a guy insulate his a while back. We used roll insulation and held it in place with chicken wire.
     
  4. omnicat

    omnicat Well-Known Member

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    Chicken Wire!! I hadn't thought of that. (D'oh!)
     
  5. quietperson

    quietperson Well-Known Member

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    We just insulated our crawlspace under our house. Went to Lowe's and got the rolls of insulation labelled for crawlspace and attics and also got about three boxes of wire hangers to hold the insulation in place. It took about half a day, but the whole underside of the house is insulated now.
     
  6. Wolf mom

    Wolf mom Well-Known Member

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    As said, I think I'd cut an entry way in a closet. That would be good also for wiring (ie: an outlet in your floor so you don't have to run electrical cords across your floor.

    Also there was a site mentioned here a few months ago about foam (that yellow stuff that expands) being sold in containers the size of a propane tank so you could insulate the underside of your house yourself. Maybe someone remembers the site.... :help:

    When you install a hardwood floor, the underlayment is rolled vynal (sp?)flooring with a spongy side. I don't remember which side goes up. I think it's the spongy side with the vynal side on the concrete as a moisture barrier.
     
  7. busybee870

    busybee870 Well-Known Member

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    id like that site for the spray foam if you find it
     
  8. crobar

    crobar Well-Known Member

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    I've been to the web site, I'll see if I can find it. I do know it costs about 1$ per sq.ft. Actually there is more than one company offering the materials on the web.
     
  9. turtlehead

    turtlehead Well-Known Member

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    We can't get under all of our house, either. It's a crawl space where you can belly-wriggle in half of it but the other half is too close to the ground. Responses to Sue's question are of interest to me, too.
     
  10. crobar

    crobar Well-Known Member

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    foam website www.fomofoam.com phone 800-339-3531, this is just one of at least 2 I saw earlier
     
  11. SolarGary

    SolarGary Well-Known Member

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    Hi,
    One way that may be less work than insulating the full floor is to turn the crawl space into a conditioned space. You do this by covering the dirt with 6 mil poly film, and sealing all the edges with caulk. Then block off all the crawl space vents, and seal up every crack and opening in the crawl space walls that you can find. Then insulate the crawl space walls inside with rigid foam board (I used 2 inch).
    This is often less work and less cost then insulating the whole floor, and a number of studies have shown that it actually does a better job of controlling humidity levels in the crawl space than venting does. Also eliminates any concerns about freezing pipes (insulating the floor can do the opposite, since it makes the crawl space run a bit cooler).

    It will reduce the heat loss through the floor, and should warm it up a bit.

    More info here:
    http://www.builditsolar.com/Projects/Conservation/conservation.htm
    Search for the word "Crawl"

    Gary
     
  12. sue currin

    sue currin Well-Known Member

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    I can't get under it because it is onle 6 inches off the ground. I have seen guys put blue foam board on the ground and the pour cement over that for gas tanks so the frost heaves don't upset the tank. I was wondering if it would work to put on the ship-lap before I nailed down a floor. I am sealing it all off on the sides with great stuff and puting tar paper down frist.