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Protecting basement polyiso from the elements during framing

airfix | Posted in General Questions on

Climate zone 6a. I think our contractors plan is to install our 1.5″ of foil faced polyiso on the inside of our foundation wall before we start framing. 

What’s the best way to protect that polyiso from the elements until we are dried in?

Is there a different sequence we can use to install the polyiso.  I.e frame the main level and roof.  Then install the basement polyiso then frame the basement?


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  1. Peter Yost | | #1

    Hi Steve -

    You are on the right track: best way to protect that PI rigid is to not install until your building is weathertight. Can you stick/stack/store a "pallet" of PI under tarp in your basement (getting it in before it becomes impossible or difficult to move 4 by 8 sheets into the space)?


  2. airfix | | #2

    I'm sure we could store it in the basement covered until ready.

    However I'm more thinking about the framing process and sequence. We have a walk out basement and some internal structural walls. I don't know if they can frame all the way to the roof without framing around the basement concrete wall.


  3. Expert Member
    BILL WICHERS | | #3

    If you have to install it before framing, wrap some poly sheet over the top edge against the wall and tape it part way down the front of the sheet. All you really need to do is make it drip tight for rain/snow protection, and make sure the bottom edge doesn’t sit in pooling water.

    If you have to stack and tarp it, make sure you put something like a pallet or some 2x4 scrap under it so that the bottom sheet isn’t right on the ground or slab where it could get wet.

    I agree it would be best to install the polyiso further along in the project though where it will be protected from the elements.


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