Jadnashua
Retired Defense Industry Engineer xxx
Right now, I have about 6" of blown-in cellulose with some R-19 fiberglass batts layed over top. I'm toying with blowing in some more cellulose. Will it be worth the effort to move the fiberglass, blow more in, then put the fiberglass back, or just leave the fiberglass there and blow over it. Goal is to get to about R-55/60 or so, so it looks like about another 7-8". Do I have that figured right?
I have four dormers that regularly get ice accumulations in the winter. Can't get to that roof, but am thinking about removing the ceiling from inside in those areas, spray foaming to seal the joints and stuff foam panels in. These dormers contain the only soffit vents in the roof system, and I'm pretty sure they're all plugged up with blow-in insulation. One of the goals is to clear that path out, ensure the baffles are intact and clear, then insulate as well as I can. Can't do all that much with the 2x6's there, though, so foam (minus the baffle path). I might be able to finagle a layer of foam on the bottom of the rafters, then put drywall back up. What would be the minimum thickness I should use there? I might need to make a step rather than having it go from horizontal to sloped, but I think the additional insulation and stopping the bridging of the wood would help. the goal is to not melt the snow, and eliminate the ice.
Right now, they installed the insulation with a layer of plastic against the wall/ceiling, then either used batts in the walls or blow-in in the ceiling. To avoid moisture problems, what would be the best stackup of materials and type of foam boards to use in this area? When the roof was redone awhile ago, they put in a full ridge vent and ice and water shield, wrapping the entire dormer and 6' up the roof, so at least now water's not getting dammed up into the walls or attic. But, the size of the icicles can get daunting!
I'd like to blow stuff into the walls, but I've got faux finish on the inside that would be impossible to match and the outside is vertical shiplap that could be 20' long and hard to remove without breaking. So, I'll probably just play with foaming the rim joist when I get around to it. Iknow I'll get more bang for the buck if I move the fiberglass to the top, but not sure it's worth it.
I have four dormers that regularly get ice accumulations in the winter. Can't get to that roof, but am thinking about removing the ceiling from inside in those areas, spray foaming to seal the joints and stuff foam panels in. These dormers contain the only soffit vents in the roof system, and I'm pretty sure they're all plugged up with blow-in insulation. One of the goals is to clear that path out, ensure the baffles are intact and clear, then insulate as well as I can. Can't do all that much with the 2x6's there, though, so foam (minus the baffle path). I might be able to finagle a layer of foam on the bottom of the rafters, then put drywall back up. What would be the minimum thickness I should use there? I might need to make a step rather than having it go from horizontal to sloped, but I think the additional insulation and stopping the bridging of the wood would help. the goal is to not melt the snow, and eliminate the ice.
Right now, they installed the insulation with a layer of plastic against the wall/ceiling, then either used batts in the walls or blow-in in the ceiling. To avoid moisture problems, what would be the best stackup of materials and type of foam boards to use in this area? When the roof was redone awhile ago, they put in a full ridge vent and ice and water shield, wrapping the entire dormer and 6' up the roof, so at least now water's not getting dammed up into the walls or attic. But, the size of the icicles can get daunting!
I'd like to blow stuff into the walls, but I've got faux finish on the inside that would be impossible to match and the outside is vertical shiplap that could be 20' long and hard to remove without breaking. So, I'll probably just play with foaming the rim joist when I get around to it. Iknow I'll get more bang for the buck if I move the fiberglass to the top, but not sure it's worth it.
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