Jadnashua
Retired Defense Industry Engineer xxx
I live in a townhouse condominium. I have a couple of dormers on each side of a Mansard roof. Long ago I added a lot of insulation to the accessable attic area and put a radiant barrier sheet under the roof joists. On the main part of the roof, I'll have snow for as much as a week after the other units have had all theirs melted off, so at least on that part, I'm fairly well situated.
The problem is on the dormers...major icicles. I neglected to knock them down as early as I should have while they were smaller, and on big one fell and bent my satellite dish, so that's out of commission until I could find a good time to have them come out. I may have them move it slightly to provide more protection, but that doesn't address the issue with the dormers, and the obvious heat leaks up there.
So, I think I'll tear the ceiling off the dormer bumpout in the bedrooms, but not sure what I'll find. I'm leaning towards putting foam sheets up there against the roof deck. There is a full ridge vent in the main attic, and the only inlet vents are under the dormers (maybe 20% of the width of the roofline). From what I remember, those did have foam channels, but no idea if they are intact (will see when I get the ceiling out).
What might be the best way to insulate and plug any air leaks into this area while maintaining any ventillation and not introducing potential condensation and rot issues? When they reroofed a few years ago, they wrapped the entire dormer, top to bottom and up onto the main roof deck with ice and water shield, so I don't expect the ice dams to have generated water damage in there. This is in Nashua, NH.
The problem is on the dormers...major icicles. I neglected to knock them down as early as I should have while they were smaller, and on big one fell and bent my satellite dish, so that's out of commission until I could find a good time to have them come out. I may have them move it slightly to provide more protection, but that doesn't address the issue with the dormers, and the obvious heat leaks up there.
So, I think I'll tear the ceiling off the dormer bumpout in the bedrooms, but not sure what I'll find. I'm leaning towards putting foam sheets up there against the roof deck. There is a full ridge vent in the main attic, and the only inlet vents are under the dormers (maybe 20% of the width of the roofline). From what I remember, those did have foam channels, but no idea if they are intact (will see when I get the ceiling out).
What might be the best way to insulate and plug any air leaks into this area while maintaining any ventillation and not introducing potential condensation and rot issues? When they reroofed a few years ago, they wrapped the entire dormer, top to bottom and up onto the main roof deck with ice and water shield, so I don't expect the ice dams to have generated water damage in there. This is in Nashua, NH.