I need to do an insulation retrofit on my house. I'm a little uncertain about what I'm doing; I thought I would run my ideas past this group.
So: the lower floor of my house is partially below-grade. The exterior walls are cinder block, and it's all beneath a wrap-around deck. We want to bump up the insulation by R-15. I live in Fairbanks, Alaska.
The plan: dig a ditch around the outside of the house and attach 4 inches of Insulfoam R-Tech to the outside walls. Cover it all up with ... something.
There is already a vapor barrier inside the wall. I don't want to make another one, correct?
Therefore, I can just scrape/brush all the crud off the outside wall, and glue (adhesive appropriate for foam insulation) a 2-inch-thick slab of R-Tech directly to the wall, and then glue another 2-inch slab to that. (Right?)
That gives me an insulated wall, but it's a bit ugly, not too durable in the event of bumps & scrapes, and can catch on fire easily. The "ugly" doesn't matter too much, since this is all under a deck. The fire hazard certainly matters. In any case, I need to cover it with something.
I'm not sure what to cover it with, though. I was wondering about getting some rolls of vinyl sheet and gluing that on. Any ideas?