Wet sheathing: Is this a problem?
I’m not sure if I have a real problem, or just a side effect of the timeline of construction. Basically, I’m looking for reassurance that this nothing to worry about, or an alarm that I need to react to this in a special way.
Location is Maine, zip 04240. I’m finishing up a room over a garage. The room is 2×6 walls with Roxul. Ceiling is Roxul, and 1 inch of foam board. Floor is 16 inches of blown in cellulose just installed last week. Heat is from a heat pump, I have it set for 62 in the day, and turn it off at night. Walls are Vinyl siding, house wrap, osb, then the Roxul and soon to be MemBrain and Drywall.
Started installing the MemBrain barrier and drywall last weekend, have almost 1 of 3 walls complete. Tonight, in preparing for this weekends work, I noticed a small wet spot on the floor in one corner,
it is about the size of a credit card. No idea how that got there, so I started poking around and
found… The exterior sheeting behind the insulation was really wet. Well, this is new, and I
suppose not a good thing. I checked around the room, on the same wall I have a half insulated stud
bay. The open half is dry, but under the insulation the sheeting is all wet.
My first thought is… Hmm, so this is why we use a vapor barrier. And it is just because I have no
real air barrier installed, physics happens. Hopefully once I get the MemBrain and drywall installed
and finished, there is no problem.
My second thought was… Crap, I’ve got a real problem that needs to be addressed before I can
continue on with the project.
I figure that the first thing someone is going to say is that I have a leak somewhere. Well, the
garage has been up for more than 10 years, and no leaks, the exterior shell is sound. I’m pretty
sure that installing the Roxul insulation didn’t create a bunch of leaks and problems with the structure. No issues until I started completing the project, I suspect the heating and outside weather is the cause, and this isn’t a big deal.
So, problem, or no problem?