2 Layers of 1″ vs. 1 Layer of 2″ Polyiso
TLDR: Is there a benefit to using a single layer of 2″ foil-faced polyiso vs. two layers of 1″ material?
I’m currently building up a materials list for a planned basement insulation job with 2″ of foil faced polyiso foam board. In going through this exercise I’ve realized that there is a significant premium placed on 2″ sheets of material at my local big box store when compared to 1″ sheets ($59.98 vs $18.98 per 4×8 sheet). It would appear that there is a significant cost savings to be had by using 2 sheets of 1″ material instead of a single sheet of 2″ material.
Am I missing something here? Or is this a clear cut case of reducing my materials cost by ~ 1/3 without affecting performance simply by choosing to use two layers of thinner material?
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Replies
More labor, but ability to offset seams.
So, if the labor is not an an issue, I see zero problems
2 in material is a complete PIA to cut cleanly with a knife, much easier to go with 2 layers of 1 in.