Foamular 250 4” 2 layers
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I am doing a garage conversion. The garage is 12” below the rest of the house and in order to avoid busting through the slab for the plumbing I want to elevate the floor about 10 inches. My plan is to use delta fl or mc moisture barrier then 2 layers of foamular 250 at 4” thick. This with 3/4” plywood subfloor on top and no framing in the room- open space studio apartment. I will then float a wood floor over the subfloor. Is there a problem with my plan. Financially it is cheaper and better insulation than framing the floor. Plus not risk of rotting my sleepers etc. thoughts?
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Replies
Stagger the joints and tape them. The problem over time will be the shrinking of the insulation as it off gasses. People here don't like XPS either. Green House gasses and all. Might be better to go with EPS. They make that in 25lb/sq in too. Less shrinking over time, and the XPS will end up at the same R value down the road, ~4 per inch. Check out Matt Risinger's video on how he did the floor in his house. Not as thick, but same idea.
If erock1297 for some reason wants to go with XPS instead of EPS, the new "NGX" version avoids the worst of the climate impact of regular XPS.