Roofing/Partial false roof
QUESTION: Hello: I live in southern Canada ~ 90 miles north of North Dakota. I have a story and a half home with a back roof that has a very shallow pitch.I have been having a major problem with ice damming at the roof's edge for decades,and have been using a snow rake for the last few winters to remove snow.For this winter,I am putting roof cables on the roof and into the gutter and downspout as a way of controlling ice damming.
There is really only a narrow strip of roof about 4' in from the gutter that is the source of heat that causes ice-damming.The roof surface is only about 6" above the interior ceilings of the house.Years ago,I had the roof opened in this area,and foam put in,but the area still lets house heat through to melt snow.
I was wondering if putting a false roof about 4-6 " high over this area would help.It would be about 5' deep and the length of the house long,about 40'. I figure it would keep snow off the warm part of the roof.The top and bottom edges would be open so rain could flow through. I could install vents in it as well for extra ventilation.Has anybody done something like this? What are your thoughts? Thanks!
ANSWER: I don't know what kind of roof you have but you did say it has a very shallow pitch. If it is very shallow then it can't be shingles. If you do shingles on a very shallow roof then it will always leak and you have the wrong kind of roof on it. Do you have shingles?
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QUESTION: Sorry,yes,it has always had a shingled roof.It doesn't actually leak,as it has an ice dam membrane covering the whole roof under the shingles.The main thing is the ice dams that form on the edge of the roof.One spring,it was so heavy it partially pulled the gutter off the roof as it melted.
I should add I DO have one area that leaks when there is melting ice,and that is around a plumbing stack half way up the roof. Last fall,I had a roofing company reseal the original stack (the house is 65 years old),but last winter,water AGAIN came in where the stack comes into the house.I hired a roof cleaning company last winter when the plumbing stack was leaking,and the dripping stopped as soon as they cleared the ice around the stack.Is there some way to successfully seal the stack so it doesn't leak? Thanks again!
A properly installed shingle roof does not need things "sealed". If you have to seal things then something is wrong. You have a 25 year shingle and a 3 year sealant. Every few years you're dealing with leaks, leak damage and you have to go up on the roof and reseal things. It's not the way to install roofs. You have the wrong kind of roof. The way to "seal" the pipe is to install the proper roof. Shingles are not sealed and a pipe is a big hole through the roof. You cannot have shingles where water backs up under shingles on a low slope roof. The lowest you can go with shingles is 2"/ft and even then you need special procedures up to 4"/ft. Above 4"/ft you can do a shingle roof in the normal way. But since you describe your roof as a "very shallow roof" I'll bet you're under 2"/ft in which case you have to install a sealed type of roof. You're hiring roofers that are steering you in the wrong direction.