Heated Roof/Gutter Cables...Questions? (shingles, heater, insulated, chimney)

[clutchrider]

I picked up a 60' cable kit from HD to put on the short roof/gutter around my chimney as I get ice dams each winter and want to alleviate having to go up there and break them down all the time.

The kit is pretty straightforward with hooks and all pieces needed except one; the thermostat. According to the manual and the piece for sale adjacent to the kit for $22 it looks like a standard 3 way plug adapter that apparently turns the unit on/off based on temperature.

So this brings up a few questions as I have never used such a device before;

1. Should I just leave it plugged in all winter or just at night or when a snowstorm/ice/rain event is predicted?
2. Is a thermostat really necessary?

[harry chickpea]

You can do it whichever way strikes your fancy. IIRC they use about the same amount of power as an old style light bulb and we just used to leave them on when it looked like there could be a problem. IMO, a thermostat is not only a waste of money but problematic. If wind whips around and the snow forms into an ice dam, you don't want the heater going off just because the temperature is 50 or 60 degrees at the wall socket. That is the time when water is most likely to be building up behind a dam and intruding.

[Nonesuch]

Most heat cable draws 5-10 watts per foot, so 60' would be +300W, maybe a buck or two a day in electricity.

Most people will just leave them on when it looks like there could be a problem, manually turn off the heat tape when there's no snow and ice accumulation to address.

[North Beach Person]

Originally Posted by Nonesuch

Most heat cable draws 5-10 watts per foot, so 60' would be +300W, maybe a buck or two a day in electricity.

Most people will just leave them on when it looks like there could be a problem, manually turn off the heat tape when there's no snow and ice accumulation to address.

This. If you run it and there's still snow on the roof it will refreeze when you turn it off and cause problems with roof leaks from the ice lifting the shingles when you turn it back on.

My mother did that and nothing I told her would make her just leave it on and her porch roof leaked all winter. Once she went to assisted living and I was going to her house every couple weeks I left the tape on and, voila, no leaks.

Of course all I told her was that I'd fixed the roof.

[exphysics teacher]

When I moved into my current home we would get ice dams and leaks. The house had flood lights on all 4 corners which we never used so I rewired them to an exterior outlet and used the switch to control them. Whenever they predict snow I flip the interior switch 6 hours ahead. I also heard that may also be an indicator of not enough insulation in the attic; so I doubled up all the attic insulation running it perpendicular to the older insulation. With last winter, not only did I not have ice dams but my heating bill reduction paid for the insulation. BTW I also bought a insulated cover for my pull down stairs.