Can I use polyiso foam for interior basement wall insulation?
A recent GBA article (http://www.greenbuildingadvisor.com/community/forum/gba-pro-help/18454/w...) discussed options for internal foam insulation on a wall already with external insulation. Another article (http://www.greenbuildingadvisor.com/green-basics/rigid-foam-insulation) tells us that polyiso shouldn't be used for below-grade applications because it can absorb water. Our design includes a poured basement wall with 4" of internal XPS foam. I am concerned about external foam being mangled during backfill. I'd prefer to use polyiso over XPS because of the higher r-value per inch, but I'm not sure if it will work well for interior basement walls.
Posted Tue, 11/02/2010 - 22:20
Edited Wed, 06/20/2012 - 11:33
Other Questions in Green building techniques