I live in northern Michigan (read COLD). I’m putting up a ‘garage’ which will be my heated shop. I’m planning a floating, monolithic slab, with one course of blocks to get the sills above grade. Here’s my question: How do I insulate the foundation.
The material I’ve read says to install a sheet of extruded polystyrene insulation around the outside of the foundation. It doesn’t say how to protect it so the sun doesn’t eat it up. I plan to sheet the walls with 7/16 OSB, then use vinyl siding over housewrap. If I use 1″ polystyrene, it will stick out farther than the vinyl siding. Can I get away with just a flashing over the foam and not worry that it sticks out farther than my siding. Seems like it may look a little wierd.
Also, any thoughts on additional insulation for the foundation?
Finally, any thoughts on the wisdom of gas vs wood heat. I plan to keep the thing at around 40 degrees when not in use, and warm it up to around 60 when I’m in there. I expect to keep a small gas heater, but am wondering if a wood stove will save appreciable $$. The shop is 30 x 40 x 10.
Thanks for the help.