Insulating attic space vapor barrier in? out? or none?
Hello,
We recently purchased a wood shingle home here in the San Francisco Bay area. The house was built in 55 and renovated in 70 it is south facing and gets a good amount of sun during the day. The house has an open beam roof and there is a loft area that was added in the 70 renovation. The plans from the house show that there is a 2″ layer of foam insulation on the roof below the shingles for the house. The loft area was built out with a dormer and has fiberglass bat insulation in the walls. The closets are in the corners eaves where the roof slopes down to the floor. they do not have insulation inside, but I want to add it as the area gets very hot in the afternoon. Should I just add unfaced batts between the roof rafters? Do I need to leave a channel above the insulation? Should I use batts wih a vapor barrier? facing in or out?
thanks!
Replies
First question
would be, is that 2" of foam still there? The roof is almost certainly not original, so changes could have been made. In any case, if there's insulation over the roof deck, there shouldn't be vent channels below the deck, so your added FG could fill the rafter bays. I would use unfaced, and if you can install drywall, so much the better.
thanks!
Thanks david. unfaced in the bays it is. I am 99% certain there is still insulation over the roof deck.