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Community and Q&A

How to insulate this stairwell

Tom Wheeler | Posted in Building Code Questions on

The stairwell is already only 34″ wide. It previously (this morning) had a 2×3 down at the turning landing and a spf 2×6 nailed to the top of the cinder blocks. Drywall covered them all around. Any suggestions on how to give this assembly some increased r-value without narrowing any more than necessary. I am pretty sure I can air seal it, but I don’t think 2 inches of polyiso is going to cut it here. Have any of you used those bean bag chair eps filler beads?  All of the cmu is exterior and covered with 30 year old 2″ xps foam.   Zone 7, Northern Wisconsin.

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  1. Expert Member
    Akos | | #1

    Provided the cells are clear, there are pour in insulation products for CMU. You can search for perlite, vermiculite or Zonolite.

    If you want to add more, when tight on space, you can also glue polyiso the CMU and glue drywall directly to that.

  2. Tom Wheeler | | #2

    I guess filling it with the shredded polystyrene and then do the gluing will be an improvement over what it was before. Thanks for the ideas.

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