Insulating hard to access attic space
In a little while I’m going to have my roof replaced. When the shingles are all off, it’ll allow me access to a remodeled section of the attic. Sometime in the past they added a better entryway, with a low pitch roof add-on. So, the pitch is low, there’s zero access from the rest of the attic, and I’m pretty sure it’s either underinsulated or uninsulated. When the shingles are off, I then can access this section and add insulation. Now, here’s the question: what kind of insulation to go with? I had been thinking to almost fill up the whole space with blown in cellulose, but that would be not very effective on the thin side. So, then… rigid foam has much higher R/inch values, but does not do as well with water vapor. So, maybe open cell foam instead?
I’ll be air sealing before I do anything, btw.