I am a licensed contractor in RI .I own a home built in the 1900's, it is a 2 story ,two family house with a gable roof and full unfinished attic. I am in the process of converting the attic to living space.
I keep ending up with condensation and wet insulation.
( I recently replaced the roof and installed cobra ridge vent along the entire ridge, with the exception of the chimney in the center.
I also cut open the wooden soffits and installed vented vinyl soffit along the entire length of the house, front and back. )
I recently insulated the rafters of the cathedral ceilings with R-38 kraft faced .
I used styrofoam baffels, every rafter bay, soffit to ridge, front and back.
Before hanging the drywall, while running electrical wiring, i noticed the insulation was wet on one side of the gable. I removed all the insulation and found moisture and mold, outside and inside the baffels. (only on the rear side of the roof) I removed everything, treated the mold, let the sheathing dry for apx 2 weeks.
I opened all exterior soffits and removed all the old wooden soffits boards and installed fully vented vinyl soffit pannels
I assumed the condensation was due to improper venting.
After improving the venting, I reinsulated the cathedral ceiling ,fully baffeled, R-38 kraft faced . and within 4 days the condensation returned, this time, only on the outside of the baffels. but only the rear side of the house. (this side gets no direct sunlight)
I do not know what is causing this or how to correct it .
Both front and back of the house are vented the same and insulated the same, the front has no condensation. the back does, even after improving the ventilation.
The roof is a 12 pitch. 2 x 10's 24" oc with cathedral ceilings. There is a very small flat ceiling along the ridge, (about 12") and knee walls at the soffit end
There are no bathroom exaust vents, venting into the soffit.