I recently installed Wrap-on roof heating cable after last year’s debacle with ice build-up. I did not purchase an automatic control unit that did not seem practical for my situation. My question is, which to me, Wrap-on did not adequately answer, when do I turn the unit on (temp)? How long do I keep it on? When do you turn it off? My neighbor keeps his plugged in all winter, but that seems like a great energy waste.
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I have ice dams on the house I'm in right now. Just in one area.
When it is cold the snow doesn't melt so you are ok.
It's when it starts to melt and then freeze that ice dams start forming.
I wait until it stops snowing.
Then I get the ladder out and rake the snow off that one area and throw some salt on it.
The salt keeps the area clear for a while and keeps the water moving.
Will Rogers
I lilke the "salt" idea, very practical, but does/has the salt done any damage/staining to the roof itself?
I have an asphalt shingle roof that is dark colored. No staining.
I did buy a bag of salt that is supposed to be better for the soil/plants though.
There was a garden center that had some. For me it lasts a couple of seasons.
Someone on this forum suggested socks full of salt as well.
You take an old athletic sock and fill it with salt.
Then you throw/put it up on the roof where the snow melts and forms a stream.
Above where the ice dams build. As the salt in the sock melts into the water it is constantly feeding the roof down below.
I did it for a few seasons but now I just rake the roof in the one area.
The raking of the area is working. It exposes the dark shingles to the sun.
We get a lot of sunny days here.
It doesn't get that cold here for very long. "There are three kinds of men: The one that learns by reading, the few who learn by observation and the rest of them have to pee on the electric fence for themselves."Will Rogers
The way to do it is to put the salt in some sort of tube -- a tube sock will do, though something longer would be better. Lay one of these on the roof every 4-6 feet, so they cross where the initial ice ridge would be. They'll keep channels melted through the ridge, so no water dams up behind it.(Same principles with heater cables -- you don't need to keep the roof edge ice-free, just melt enough channels through that no water gets dammed up.)
A society that presumes a norm of violence and celebrates aggression, whether in the subway, on the football field, or in the conduct of its business, cannot help making celebrities of the people who would destroy it. --Lewis H. Lapham
When it is warm enough to melt they need to be on.
I turned them on when it got close to 30 degrees.
They are not supposed to be left on above forty I think.
The particular brand i had specifically said to plug it in before
the snow built up.
something about how they are not designed to melt a pile of snow.
I've never had one where the thermostat was not built into it
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Yeah, it's an extra $60.00 now.
Actually the good one is about $75.00 but it detects moisture and temp which saves on electricity and helps when no one is home to plug in. On installation in Ma. it requires a special GFI breaker with a lighted switch and the plug mounted at least 6' off ground. The breaker is about $ 145.00
Simple answer: You turn it on when you need it and off when you don't need it. Temperature is only one factor -- you have to consider sun and the time of day as well.
You turn on the heater when it's warm enough (given the sun) for snow to be melting up the roof a bit, but cool enough (down at the eave, and maybe under a layer of snow and ice) for meltwater to refreeze. Often this occurs in the late afternoon, but it can occur at other times of the day depending on temperature and sun conditions.
Could another factor in my ice damming problem be poor insulation from a still roughed-in ceiling/wall area that I am still working on. I have insulation -taped it as best I can, but I have no drywall up yet (walls/ceiling) and fear that heat loss is causing the melting/damming regardless of the weather outside... I may be causing the problem with this yet unfinished project.
I had ice dams form above windows in Wisconsin.
The windows were facing south so there was enough heat form the windows and the Southern exposure to melt it in the daytime.
But overnight it froze. So they did build up.
In Wisconsin it wasn't uncommon to see guys raking certain parts of their roof.
It was a cheap way to prevent ice dams. The old ways are more work but are cheap.
In Wisconsin people liked to get out after a snow. "There are three kinds of men: The one that learns by reading, the few who learn by observation and the rest of them have to pee on the electric fence for themselves."Will Rogers
Definitely, poor insulation and lack of attic ventilation (in a "cold" roof) can lead to ice damming. Eliminate these problems and you eliminate about 90% of ice damming.You can still get some ice damming, though, just because of odd roof angles and the way the sun hit -- top of the roof in the sun and the eave in the shade.
A society that presumes a norm of violence and celebrates aggression, whether in the subway, on the football field, or in the conduct of its business, cannot help making celebrities of the people who would destroy it. --Lewis H. Lapham
with my old house there was a section of the roof that was pretty close to flat and it had massive overhangs..
Can you say Ice Dams?
My solution was far more energy efficent plus it cost a whole lot less.
I took some water softener salt and put it in a couple pair of my wifes panty hose I cut off each leg (of her panty hose you creeps <grin>) tied a knot in the cut end and tossed them up on the roof(vertically)
Then all winter long I had 4 channels to allow melted water to flow down and keep from leaking back into the roof..
What's more because it was so close to flat nobody but me could see them from the street..
I wish I knew how much they cost because I used the ones my wife got runs in and was going to throw away. plus I don't think I used even 1/2 of a bag of raock salt.
OK I suppose it cost me $2.50
Your stocking sock solution was great! But did you fill those stockings with water-softener salt or regular rock salt? Did the one sock work for the entire season or did you have to refill/ renew during the winter season?
water softening salt leeches out slower, One year that had a massive amount of freeze thaw I had to recharge it when I used rock salt..
So if you have a massive amount of freeze thaw go to water softening salt otherwise use rock salt either case one stocking filling is all you need..
The answer to your question depends a lot on the exact brand.
Whatever the make, there is some manner of regulation built in. This ought to turn the unit off when it's above freezing.
Before I really discuss it, though, I simply MUST know what product you used.
The brand is WRAP-ON and I used 100' length. Nothing in the literature mentioned any automatic on/off mechanism.. I think they want me to purchase their "roof sentry automatic sensor" device...sold separately.
You're correct .... it's not a product I would reccomend.
All that cable does is make heat ... if it gets too hot, it will fry itself. Leave it on over freezing, it dies. Let the wires cross over each other, it dies. You really do want to use their controller with it.
There are better tapes out there, that do not have these problems. For you, that's water over the dam. For everyone else, bite the bullet and get the RayChem self-regulating, idiot-proof tape.