OT: Roof heating cables

[rpm]

I'm looking for advice on roof heating cables to put on the edges of the roof and in the gutters. My house has a very shallow pitched roof, and we have chronic ice dam problems. We've ventilated, insulated and sealed heat leaks, but the roof is still prone to ice dams. My roofing contractor suggests putting in heating cables along the edge and into the gutters and downspouts. Does anybody have experience with these?

[chuckred]

We used them on many of the condos that had ice damming problems along the eaves and also valleys of the roofs. It's been 25 years - so no doubt they have some new technology - but as I recall, you could either go with thermostats or always on - then either put on a timer or switch.

Biggest thing to watch for is to be sure your outlets can handle the load.

I've also seen at plumbing supply shops - you can buy it by the roll, then cut to fit - may be more cost effective than the ready made stuff. They could give you the scoop on how long of a run you can use.

[1centaur]

I had them and now I don't. I have a rubber membrane high enough under the shingles that no ice dam can get high enough to let water in. Fact is that wires sometimes work well and sometimes do not - depends on the freeze/thaw combo and the amount of snow and timing of each. Membranes get me past that worry. The one exception might be the gutter itself, since gutters are often the biggest reasons for ice dams.