Ice Dams on Roof

[PAJerry]

We are having a real problem with ice dams forming on our roof. The house style, 1 1/2 story cape cod, is very difficult to insulate correctly, since only about 1/2 of the rafters can be accessed. There is a hallway and bedroom upstairs that we can't get access to the rafters, but the edges are well insulated dince there is a crawl space access there. The ice dams form on the edge of the roof, but also halfway up the roof due to snow melt off the uninsulated upper section. The problem is more severe this year since we are using the insert 24/7 and the chimney, which runs up the middle of the house and is exposed, is quite warm, making the snow melt on the roof. We have asphalt shingles and apparently water is backing up under the shingles and we have had dripping in the kitchen and one bedroom.
I'm wondering if there is a safe way to insulate the chimney to prevent heat loss and stop the snow melt. We are also seriously considering installing a metal roof, since snow doesn't stick to it and can be more easily roof-raked off. I have been using the roof rake this year but the dams still formed. We get about 120 inches of snow here and seem to be getting above normal this year. We never really had a problem except when we used the fireplace a lot before the insert went in. Used to keep the house at 62 using the boiler, but now keep it at 70+ with the insert.
If anyone else had a similar problem, I am very interested in how you solved it. Any ideas are welcomed.

Jerry

 

[Rich M]

We have an old cinder block on slab house (i.e. all heating ducts in the attic) and have always had ice dams. With an average snowfall of 160" + in the snowbelt where we are, a metal roof was the only solution. Lifetime warrany, hurricane rated and looks great on an older home, the (substantial) expense can be off set by increased property value.

 

[got wood?]

I've seen folks get those long heat-tape style setups and tack them in a wave-like pattern to the last 6' of roof before the gutter. I would imagine they are controlled by some simple thermostat of sorts to prevent snow and ice from sticking where the ice damming occurs. No idea how much electricity they consume...probably less than a new roof tho ;-)

 

[Greg123]

We are having a real problem with ice dams forming on our roof. The house style, 1 1/2 story cape cod, is very difficult to insulate correctly, since only about 1/2 of the rafters can be accessed. There is a hallway and bedroom upstairs that we can't get access to the rafters, but the edges are well insulated dince there is a crawl space access there. The ice dams form on the edge of the roof, but also halfway up the roof due to snow melt off the uninsulated upper section. The problem is more severe this year since we are using the insert 24/7 and the chimney, which runs up the middle of the house and is exposed, is quite warm, making the snow melt on the roof. We have asphalt shingles and apparently water is backing up under the shingles and we have had dripping in the kitchen and one bedroom.
I'm wondering if there is a safe way to insulate the chimney to prevent heat loss and stop the snow melt. We are also seriously considering installing a metal roof, since snow doesn't stick to it and can be more easily roof-raked off. I have been using the roof rake this year but the dams still formed. We get about 120 inches of snow here and seem to be getting above normal this year. We never really had a problem except when we used the fireplace a lot before the insert went in. Used to keep the house at 62 using the boiler, but now keep it at 70+ with the insert.
If anyone else had a similar problem, I am very interested in how you solved it. Any ideas are welcomed.

Jerry

PAJerry I posted about this question awhile back and got some real good advise, I hope this helps

https://www.hearth.com/talk/threads/2547/

I ended up just using heating cables this year which have worked well for me.

 

[begreen]

I'm wondering if there is a safe way to insulate the chimney to prevent heat loss and stop the snow melt. We are also seriously considering installing a metal roof, since snow doesn't stick to it and can be more easily roof-raked off. I have been using the roof rake this year but the dams still formed. We get about 120 inches of snow here and seem to be getting above normal this year. We never really had a problem except when we used the fireplace a lot before the insert went in. Used to keep the house at 62 using the boiler, but now keep it at 70+ with the insert.
If anyone else had a similar problem, I am very interested in how you solved it. Any ideas are welcomed.

Jerry

Can you blow in insulation into these cavities? I'd get a good insulation contractor out there. Take pictures now so that they can see where the problem spots are. It only takes about a 1.5" hole per cavity. In a pinch I would think one could do it through the ceiling if necessary.

 

[Roospike]

What about concrete board box around the chimney pipe in the attic ?

 

[PAJerry]

Chimney is double course of bricks with 2 - 9 x 13 tile liners. The insert flue has an 8" oval insulated stainless liner. I am thinking of attaching 3" of polystyrene insulating panels to the bricks to prevent heat loss to the upstairs. The chimney is not 'hot' but just quite warm to the touch, but because it runs about 12 ft. up from the base of the stairwell to the roof, it loses a lot of heat. Anyone see any problem with doing this?

Thanks for all the suggestions so far. This problem is very aggravating. I did go up on the roof this morning and broke up the dam that was leaking into the kitchen and the forecast is for warmer weather later this week. I raked off all the snow so only a few ice patches remain, and the roof is dark brown so hopefully the sun will do the rest.

 

[Roospike]

Are you getting proper ventilation in your attic ? No vents covered with insulation or such ? correct size vents ?

 

[ansehnlich1]

You got any soffit up there? Do you have insulation all the way to cover the soffit? If so, that could be part of the problem. You should have, inside, a passageway for air to move there.

I recall in Maine many homes having sheetmetal along the lower couple feet of roof, then the shingles start on up. Guess that metal is to get the frozen stuff to slide off there.

I think you have a ventilation problem perhaps.