XPS versus EPS Underslab Foam
Hi. I am back and forth on whether I should use XPS (blue board) or EPS for the insulation underneath my slab. I understand the qualities of each regarding water absorption and drying out, but would it (XPS particularly) affect the long term performance to the point where the slab is compromised? I also understand the pollution associated with XPS manufacturing. I have the option of purchasing 6" (house in very cold climate) of EPS (R-24) or 4" of XPS (R-20). The EPS is less expensive per inch, however, I need to pay for shipping which jacks up the price. It may be difficult to compare apples to oranges in this case, but when looking at R-value alone (and without heat load calcs performed), do you think I can recoup the $1000 more that I spend for the EPS for 4 extra "R's", in energy savings, or go with the R-20 XPS and save upfront? Any thoughts out there? Thanks in advance. The Q&A section of GBA has been very helpful.
Posted May 2, 2014 12:34 PM ET
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