Plastic Under Roof Air Channels
I’m about to insulate a 2nd story gambrel roof shed. I have the thin black air channels in between the 16″ o/c rafters. Next to the top plate and floor decking there are openings between rafters for screened soffit venting. The plastic vent channels don’t take up all the venting opening.
With 6″-R-19 vapor barrier fiberglass batts, placed over the top of all the vent channels, do I leave the extra opening area at the bottom of the plastic channels aren’t using or should I foam closed the remaining open area to keep the fiberglass from getting moisture and air between the bare fiberglass and roof deck?
Bill
Bill
Replies
I'd consider blocking off what doesn't line up with channel. Reasoning that air infiltration directly into 'glass would compromise its function somewhat.
I'm curious where your channels vent at the top , do they run the length of the rafter bay?
Everything will be okay in the end. If it's not okay, it's not the end.
I'm curious where your channels vent at the top , do they run the length of the rafter bay?
There's an 8' ceiling in the top floor. The vents run the length of the first angled roof and passed the half way point of the top angled section; the joint/splice is sealed with metal duct tape. The insulated 2ft space above the collar ties/ceiling joists has ridge and gable venting the length of the building.
thanks,
bill