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Insulating basement with 5″ EPS

paul_miltenburg | Posted in General Questions on

I came across some used 4×8 sheets of 5″ type 1 EPS and was wondering about insulating my basement with it.  Being so thick, I’m not sure what the best approach is; here’s two thoughts I had:

1. Fasten the sheets to the wall with 2×4’s on the flat, using 1/4″ threaded rod type anchors.  Drywall would then fasten to these 2×4’s.  Electrical could be done with shallow boxes.  The anchoring would be tedious, but the foam would be continuous with a lot less cutting.

2. Frame a conventional 2×4 stud wall with the inside face about 6″ from the concrete and cut foam to fit the spaces.  The gap behind the studs could be filled with 1.5″ foam or spray foam.  Electrical would have to be notched into the foam. 

Maybe someone has a completely different approach?  What’s the best way to cut foam this thick and maintain square cuts?

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  1. Expert Member
    NICK KEENAN | | #1

    How about a wall made from the 2x2 sized steel studs, attached only at ceiling and floor? Attach a track to the ceiling joists. At the bottom you could attach the track directly to the concrete, although I find it easier to attach a piece of wood to the concrete and then screw the track to the wood.

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