Moisture in cathedral ceiling assembly
Hi. We have a 1951 brick cape which we have been renovating for several years. We have a small area in the valley of two gables that was turned into a small storage area between rooms. The area was previously very poorly insulated, so we had filled it with rock wool and in some cases, installed baffle vents (more on that below). Because we were tired of “improving” and didn’t want to fully demo the rooms, spray foam, etc, we tried to do the best we could with what was open.
I had posted some questions last year, more or less after it was too late, and was advised that putting in the baffles in an area with no soffit was useless. This year I decided to better seal the area to keep any cold air from coming into the room from the storage area ahead of building a door for it. Figuring the baffles were just letting cold air into the area from the attic, I pulled one out, and was horrified to find condensation on the warm side (between the baffle and the rock wool). I decided to dig around other areas , especially where I had just applied FB batts, and found a light coating of frozen ice pretty much everywhere. Merry Christmas!
So now I have to figure out what to do (besides maybe scrap this whole idea of a conditioned storage area lol. Was I better off having the baffles in there, as at least the water was condensing on the baffle and not the sheathing? I understand the RIGHT way would be to pull it all down and spray foam or cut & cobble (I have read all the blogs) but it’s a little too late for that now as the rooms are finished. I suppose I could decide to gut the area fully and do the full treatment in a few years, but doing so now would be extremely disruptive (not to mention divorce inducing :P)
So I guess one more question is, is it typical for cathedral ceilings to get SOME condensation that just dries naturally? One thing that I can’t quite fathom is that for 60 years this same area was insulated in more or less the same way (admittedly not very well) with Balsam Wool. Unless it allowed THAT much more airflow between the insulation and sheathing, I can’t believe this is the first time that this has taken place. The sheathing in this area is 50’s era T&G 3/4″ planks, and I can’t see any evidence of mold or rot at all.
Sincere thanks as always for any advice!
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