# Foam Insulation Questions - Please help



## Beepster (Oct 19, 2009)

After tons of research at this site and all the attached "Building Sciences" links provided by GBR, I went with 1" XPS glued to the block walls and will 2x4 frame over that. By going only 1", I will need to monitor the humidity in the summer and keep it below 50%. There is an adhesive amongst the million different tubes at the big box stores specifically for foambaord (ML300??). Do not cut channels in the foamboard, you would defeating what you are doing. 2x frame over and run your elect as it was. Rewire with romex if necessary.

B


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## Windows on Wash (Aug 30, 2011)

+1 to Beepster's comments as well.

2" would be fine as well and still keep you at about 0.6 perm rating.

Make sure the ribbon boards are sealed up properly as well.


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## Gary in WA (Mar 11, 2009)

Yep. I'd check on that brand foamboard, though. I believe it is faced with a poly, which you don't want below grade: http://www.buildingscience.com/documents/reports/rr-0202-basement-insulation-systems An alternative is ESP, but make up the R-value for your location.

Gary


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