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Basement Insulation

Post in 'The Green Room' started by jlmilligan, Jul 22, 2008.

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  1. jlmilligan

    jlmilligan New Member

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    I am considering insulating my basement. Just wondering if anyone has any other ideas or input on payback. Here are the details: basement is 1536 square feet with radiant heat in the slab. I currently keep the basement temp at 62 degrees. One 28 foot section is stick framed and the rest is 8" concrete wall aprox. 8 feet tall. I was thinking I will put up 2" styrofoam T&G;panels held in place with 1" x 3" strapping. I figured it will cost around $450 to $500 bucks. What are your opinions on sealing the walls first? They were sealed with the black tar from the outside before it was backfilled and my basement has always been dry.
    Thanks for the input.

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  2. Doing The Dixie Eyed Hustle

    Doing The Dixie Eyed Hustle Minister of Fire

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    What's the temperature, when the weather is at it's worst, if you don't have the heat on?
  3. iceman

    iceman Minister of Fire

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    if you have a stove down there do it.... if you heat it with oil do it
    if you wanna save money use regular insulation and just compress it .... you won't get the r value as advertised but will be at least eq to 2in styrofoam but a lot cheaper .....and run a humidifer you'll be surprised
  4. velvetfoot

    velvetfoot Minister of Fire

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    I've been thinking about doing this too, though I have no radiant heat.
    Sheetrock covering is required, I've read. Then you'd route the electric wires in the space created by the T&G;strapping?
    Radon is a problem around here and something to think about, as in sealing cracks and coating the walls, etc, if only for resale.
    I am able to control the radon with a pump sucking air through a pvc pipe through the floor slab, and my basement is also dry, knock on wood, so I don't think I would coat anything.

    It won't be as cool down there in the summer though, will it (if that is a factor)? You would think it would stay drier since not as much condensation.
    Thing is, I already have an insulated basement ceiling, so that would kind of create an independent insulated space, which I don't know if good or bad.
  5. velvetfoot

    velvetfoot Minister of Fire

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    In my last place we had foil batts in the basement, that didn't require covering.
    It always stinky down there in the summer though, and I blamed moisture condensing in the fiberglass which was against the concrete.
    I figure styrofoam should support mold and maybe the paperless drywall as covering wouldn't either.
    The sheetrock covering would be a hassle though, just for fire proofing.
  6. ms440

    ms440 Member

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    After your ceiling the basement is the second most important area of your home to insulate assuming that your floor is not insulated. One inch of solid foam will give you r5 which equates to a 70% decrease in heat loss for your basement. You can not affor NOT to if you are heating your slab. 2 inches is better than 1. Another options is to use 1 inch foam and then stud a wall in front of it and insulate with UNFACED insulation and then sheetrock. You do not want any vapor barriers in your basement wall system. Period. One half of the year vapor wants in, one half of the year it wants out. Good luck.
  7. WILDSOURDOUGH

    WILDSOURDOUGH New Member

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    Your plan sounds good to me. I just finished building- have ICF foundation w/ raident in slab- which is kinda the same principal- 'styro on concrete'.
    Finished bath and man-cave with T&G;pine attached to strapping attached to plastic 'studs' built into styro.
    Only problem I have with water is blowing in through walkout french doors when it rains from the west- so basement is dry and don't have to use a dehumitifier.
    Insulation is always a good investment.
  8. jlmilligan

    jlmilligan New Member

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    Thanks for all the replies. I have never left the heat off to know what the temp would be without. I would assume in the low 50's or lower. I live near Bangor Maine and it does get pretty cold here. The ceiling of the basement is insulated because I have radiant heat on the first floor too. I would prefer not to stud up a wall because it would eat up precious space. (no garage so all storage is in basement) One thing I dont understand is that T&G;pine is ok for a wall covering rather than sheetrock. That doesn't seem any more fire resistant then foam. Anyone with experience with gorilla glue. I have heard of people attaching the foam to the wall will it and was wondering how well it holds. So far the foam still seems like a good idea.
    Thanks
  9. velvetfoot

    velvetfoot Minister of Fire

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    I don't know about that glue, but it has to be compatible with the styrofoam.
    I think that those spray insulation foams are, and it sure is sticky.
    The problem is, you still have to cover it with something.
    It'd be interesting if you could just glue everything, but I've read that's not considered good enough., so you'd need the studs for the sheetrock.
    Maybe that planking is good enough for a fire barrier, I have no idea, but if the inspector okayed it, it must be okay.
  10. jlmilligan

    jlmilligan New Member

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    my basement is split into 3 rooms. Boiler / oil / well room, storage / workshop room, and the rec room. I was hoping only the boiler room would need a wall covering but I couldnt get a straight answer. In the rec room, I would like to do v match pine mainly because I HATE mudding sheetrock. He did say that that would be fine. I would be happy just glueing some panels up and leaving it that way in the workshop area. It would cut installation time down. I will pass on any info I can get. Thanks
  11. begreen

    begreen Mooderator Staff Member

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  12. iceman

    iceman Minister of Fire

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    [quote author="ms360" date="1216788689"]After your ceiling the basement is the second most important area of your home to insulate assuming that your floor is not insulated. One inch of solid foam will give you r5 which equates to a 70% decrease in heat loss for your basement. You can not affor NOT to if you are heating your slab. 2 inches is better than 1. Another options is to use 1 inch foam and then stud a wall in front of it and insulate with UNFACED insulation and then sheetrock. You do not want any vapor barriers in your basement wall system. Period. One half of the year vapor wants in, one half of the year it wants out. Good luck.[/quote



    no vapor barrier...uhuh mine has it what do i do now
  13. velvetfoot

    velvetfoot Minister of Fire

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    Reviving this thread.
    I'm finally getting around to doing something, but darn, stuff is expensive.
    What can be used to glue the foam board (Dow Corning Foamular XPS) to the concrete wall, prior to attaching the furring strips?
    Also, the glue could attach foam pieces to each other for sealing.
    I was going to try the Great Stuff brand foam as a glue, but was wondering if anyone had actual experience.
    Thanks.
  14. Highbeam

    Highbeam Minister of Fire

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    My buddy is attaching the XPS board to his stem walls right now with liquid nails. The tube label actually lists XPS foam as a suitable application. It was a treasure hunt for him since some off brands of construction adhesive were not suitable for the XPS.

    In two days I will be helping him pour the slab over the top of all of the foam and radiant tubing for his floor under the entire home. I'm pretty excited to see all the pipes set up.
  15. velvetfoot

    velvetfoot Minister of Fire

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    Thanks. Dow says anything not containing petroleum for its foam insulation.
  16. velvetfoot

    velvetfoot Minister of Fire

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    I just got a few 2 inch panels from HD.
    I saw some glues made for foam.
    Also, saw that polyurethane glue, which can be bought in big tubes for a caulk gun, will work.
    In fact, polyurethane is probably the Cadillac of glues, and like a Cadillac, is not cheap.
    Maybe glue isn't even that necessary, with the furring strips holding it on. However, maybe it is needed to prevent air from getting behind the foam onto the concrete.
  17. precaud

    precaud Minister of Fire

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    Both HD and Lowes sells PL, and they make PL300 Foamboard adhesive. I used it with the Dow blueboard and it works great. Inexpensive, too.
  18. velvetfoot

    velvetfoot Minister of Fire

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    Thanks much.
  19. velvetfoot

    velvetfoot Minister of Fire

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    I forgot to ask if and how you braced the board to the concrete or did you fasten it down mechanically right away?
  20. precaud

    precaud Minister of Fire

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    The Dow blueboard is tongue and groove. I cut it for a snug fit top-to-bottom, so I only glued a couple spots of each sheet to the wall, and then glued along the entire edge of each one. I put up all the foam board first and then put in the furring strips. Have yet to sheetrock over it...
  21. velvetfoot

    velvetfoot Minister of Fire

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    Thanks very much again.
  22. precaud

    precaud Minister of Fire

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    Good luck with your project - you'll be glad you did it!
  23. Highbeam

    Highbeam Minister of Fire

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    I couldn't find the BIG tubes of PL300, only the dainty ones. If that matters to you.
  24. velvetfoot

    velvetfoot Minister of Fire

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    HD had some big tubes of the polyurethane.
  25. sinnian

    sinnian Minister of Fire

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    THE most important place to insulate is the sill plate, however to do it correctly (i.e. no air leaks) is to use the spray foam, and for the amount of space it is cost prohibitive for the homeowner to use cans. It is best done by a professional. There is so much air infiltration and loss through your sill plates that it is actually more important to insulate that area before even adding any to your attic.
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