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kiwigem_gw

Fiberglass insulation on exterior foundation???

Kiwigem
9 years ago

Hi!,
So I just went over to look at our foundation, and was expecting to see a foam board insulation on our exterior foundation walls, and instead I see what looks to me like fiberglass batt. Please tell me there is something appropriate for exterior below grade foundation insulation that looks like that and what it is! yikes.
Thanks!

Comments (11)

  • millworkman
    9 years ago

    Not that I have ever heard of. F/G insulation is not for exterior below grade period from what I know (and really should be covered with something for interior applications). You probably need not worry though because I don't think there is any chance the building inspector would give your foundation "Waterproofing" an approval like that. However with that being said I would be throwing up red flags that a GC would use a mason contractor who thought this would be acceptable!

  • Kiwigem
    Original Author
    9 years ago

    I found out it's called Warm N Dri board. Thanks for chiming in, Millworkman. I'm ordering my windows today, so thanks for your help on that, too.

  • millworkman
    9 years ago

    No worries and your welcome, glad you found out what it was. I have not heard of this product so I will need to Google it. By the way what windows are you going with?

  • Kiwigem
    Original Author
    9 years ago

    Integrity wood ultrex casements on most windows (all-ultrex in garage, basement, and bathrooms). Full Marvin (I love saying that- sounds like Fully Monty) patio sliders. All in bronze with no grills. Going to have drywall returns and paint interior frames dark to mimic the look of steel windows.

  • Brian_Knight
    9 years ago

    The generic name of that product is mineral wool. It certainly does have the appearance of FG but has much different characteristics. Its long been used in that application because it offers drainage and insulation. Probably not as much insulation as you should have in some folks opinions..

  • Kiwigem
    Original Author
    9 years ago

    Thank you! I am told the R value is 10.

  • millworkman
    9 years ago

    Excellent choice in my opinion on the windows Kiwigem. Please post picture what they are in, during construction and finished if you can.

  • renovator8
    9 years ago

    Warm-N-Dry rigid fiber glass insulation board has been offered by Owens Corning as foundation insulation for several decades. It primary feature is rapid water drainage due to the layering of the fiberglass mats.

    It was originally promoted with a cold spray-on modified-asphalt waterproofing product from Koch Waterproofing called Tuff-N-Dri (now owned by Tremco). I have used these products together and they are very cost effective.

    A thickness of 2 3/8" is needed to get an R value of 10.

    What did you use for waterproofing?

    Here is a link that might be useful: Warn-N-Dri

  • Kiwigem
    Original Author
    9 years ago

    Renovator8, you are a treasure trove! Waterproofing is spray on black stuff that looks like tar. I think it was Tuff N Dri, as you mentioned.

  • renovator8
    9 years ago

    That's great. IMO there's no better residential waterproofing than cold spray-on modified/rubberized asphalt. Unfortunately it is incompatible with polystyrene thus the use of fiberglass board.

    However, a non-PVC drainage/protection layer could be installed between the waterproofing and the polystyrene if you don't mind mechanical connectors.

  • energy_rater_la
    9 years ago

    thanks Reno8.
    not that we insulate foundations...but
    nice to know. good stuff you contribute!!