Should I correct the ductwork or the un-insulated walls or both?
We live in Hudson, Quebec between Montreal & Ottawa. My plan is to insulate walls of 2 rooms, from the inside, using 2″ EPS Type I insulation, covered with a reflective vapor barrier directly on the existing drywall and 1″ furring strips and 1/2 drywall. These rooms have 2 “exterior walls” each and tend to be more humid and cold than the other rooms.
The exterior walls are concrete block covered with traditional stucco. There is currently 2″ of air space behind the concrete blocks, then 2 layers of ½” drywall. In addition, there is a loose black sheet of some kind of paper material behind the drywall. I am not sure if this is a form of vapour barrier or not. The house was built in 1959.
I am worried about potentially creating a moisture problem somewhere within the assembly.
Also, we have forced air heating and the ductwork is in the attic. I insulated the ductwork three years ago, with R30 fiberglass insulation. However, the heating vents are at the top of the walls close to the ceiling and the returns are at the bottom, either on the walls or in the floor. The duct work for the returns are in the crawl space which is about 2 to 3 feet high. The crawl space walls are insulated with blue sprayed insulation. There isn’t insulation beneath the floors and floor of crawl space is sand with vapour barrier over it. Our floors tend to be cold almost all year round. There is a return in every room except for the kitchen.
So the question is, should I be more worried about correcting the ductwork or the un-insulated walls?
We hope to live here for a long time – say at least 5 to hopefully 20+ years. Note: As it is, the house stays cool during summer – so no need for air conditioning.
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