I have a sunroom which has a common wall with my garage. The sunroom was originallly just an open porch, so the common wall with the garage was never insulated. I eventually added heating and A/C to the sunroom so we could use it year round. The celing of the sunroom is insulated to R-40. But I want to do something with the wall.
My initial thought was to add 2-inch foamboard to the garage side of the wall, folowed by a new layer of drywall. Or I could fur out the garage side of the wall and add fiberglass insulation and then drywall. I want to do the work myself, so I am not considering spray foam. I want to be sure that I am not creating a situation where moisture would be trapped between the original wall and any layer I add. And of course the wall needs to remain fire-rated.
I am in Kentucky, so require both heating and cooling for the sunroom. The garage goes below freezing only on extremely rare occasions. Grateful for any idea and advice.
Replies
Why not..............
bore holes in the drywall on the garage side, blow cellulose, patch the holes?
Thanks
Thank you; I will look into that.
In this situation it's unlikely that moisture would be a problem in the winter. Neither the garage nor the sunroom "generates" moisture to any degree (unless you use the sunroom for a greenhouse), so, assuming that the door between the sunroom and house is kept closed in cooler weather (and you're not heating the room with forced air from the house), the dewpoint should never be much higher than outside, and condensation would be impossible. Even with some of those assumptions violated, though, your idea of 2" of foam should be totally safe.
For summer you wouldn't have any chance of condensation in the wall when there was no condensation on the sunroom windows, but I'm guessing that window condensation may occur from time to time. Again, however, a 2" layer of foam on the garage side (covered with drywall) could never lead to condensation in any reasonable scenario.
Thank you.
Thanks for your comments -- they clarify the situation.