Is it recommended to divide the insulation values between XPS foam board and fiberglass for a basement wall in Zone 6, and is it acceptable for them to touch?
Asked by Hermann-Josef Heinecke 
2 months ago
Last Updated: October 27, 2024
We’re looking to insulate our basement wall in Zone 6 and I’ve heard that the recommended R-value is 15 for basement walls. Does that sound right to you? If we’re thinking of using XPS foam board and fiberglass, how should we divide the Rs? For example, would it be okay to have an R-value of 5 in the foam board and 10 in the fiberglass? And is it okay for the foam board and fiberglass to be touching each other? Thanks so much for your help!
Attach the foam board to the concrete wall and place Fibreglass insulation between the studs, either R15 or R20 depending on the structure of your framework.
I heard they have a model specifically for 2×4 walls called R21.
Haven’t come across that in my neck of the woods yet haha.
Got it, thanks!