I’m new to this forum and looking for some thoughts on a possible upcomming project on my own house. Any comments would be appreciated.
I’m needing to re-shingle my roof this summer and am considering my options for adding ventilation to an older house. My current roof has very little to no venting and considerable ice dam issues. One option I’m considering is building a cold roof on top of the existing structure. I would lay flat 2×4 sleepers accross the roof, lay new 2×4 ‘trusses’ on edge above the old trusses, re-sheet, tar papper, shingle. This would also allow me to increase the 8′ overhand to 16′. I would vent at the eves and along the ridge.
Does anyone have any experience building this type of roof system? Is it likely to solve my ice dam problems and give me the venting I’m looking for? Should I remove the old shingles if I go with this option??
Replies
Some one else will chime in here soon, but from what I know, a cold roof would solve the ice dam problems. There are other issues (expense, how to deal with the extra thickness cosmetically, etc.) that should be addressed.
Can I get that Little Debbie snack cracker out from under the heel of your pointy boot?..
http://grantlogan.net/
"an older house...and considerable ice dam issues."
Not to discourage you from venting, but if you have ice dam problems then it is likely that you are losing a lot of heat from your living area into your attic.
You should inspect your attic floor (actually the living area ceiling) for air bypasses (holes). If the house is really old, then it might be balloon framed and the tops of the walls have no top plate. If that's the case, then there is a ton of air moving into the attic.
Anyplace where wiring or plumbing come into the attic through the top plate usually allows air to move through the hole.
Ceiling light fixtures and ceiling fans often allow air into the attic at the fixture box. Recessed lights are notorious for this, but must be treated carefully so as not to cause too large a heat buildup (build a generous box out of drywall around the fixture.
Just putting insulation in the attic won't help with this. The holes must be sealed...usually with foam, on large holes a plastic shopping bag filled with cellulose stuffed into the hole (maybe with some foam around the edges), at the chimney use metal and heat resistant caulk.
Your cold roof idea will stop the ice dams, but it won't stop the money you lose heating air that is escaping into your attic.
Rich Beckman
Another day, another tool.