Hello, I want to insulate the rest of my basement above grade. The previous owner dug out the foundation, applied water proof membrane, insulated with 1.5” or 2” of foam, added drainage pipes and backfilled with rock. They didn’t go above grade though so I want to do it from there to the bottom of the siding. House is in zone 7 so very cold. How thick if foam should I go? Code says R-20 but that’s 4” of foam.

The problem is I haven’t been able to find a good way of flashing this junction where the foam meets the siding. The foam is going to stick out past the siding as well. I don’t want to remove the siding as it will probably break its thin redwood siding that is old and dry.

The foundation above grade is skim coated and painted, do I need to put down a waterproof membrane first before the foam?

What do you do at windows? How do you frame them out?

What are my options for protecting the foam that is not a stucco like coating? I fear anything applied like that will eventually start cracking off. There is a foam board that comes pre-coated with small rocks or stucco that would work but it’s only 1-2” thick. I also saw this plastic roll that you fasten to it but it’s pricey. Can you use that vinyl stone siding stuff?

Thanks!