How do I fix condensation between ceiling and closed cell spray foam insulation?
I have cathedral ceilings on my second floor with close-cell spray foam insulation on the bottom of my roof. There is only about a 1-2 inch gap between my ceiling and my “hot roof.” I had the roof done 4 years ago and it is completely covered with ice and water shield. Over the past few months (covering the spring and summer), I have noticed water stains and mineral effervescence pushing through the paint on the very highest point of my ceiling. I have asked the contractor to remove the top 3 layers of shingles to see if there was anything wrong with the exterior. That is supposed to be done soon. If there is nothing found up there, he suggested that I will have to run the bathroom exhaust fan constantly to remove humidity. I have two questions about that: #1. How will that help during summer months when all the windows will be open? #2. How will that remove any condensation that is accumulating above the ceiling in the small space between the ceiling and spray foam?
Has anyone experienced this issue or have any suggestions? It’s so weird that it just started happening after 4 years. It’s difficult to tell if it’s rain or condensation as we’ll have some really humid days here in Massachusetts and then it’ll poor buckets right after.