Roof De-icing

[cjn1014]

I've had reoccurring problems with a section of roof in a house be purchased two years ago. We had to strip and reshingle this portion due to previous water and ice issues the home inspector missed. I pretty much have everything working against me; addition, high vaulted ceiling, no access to the void space, north facing exposure, and a higher roof above that catches plenty of winter sun and drops meltwater on the constantly shaded section. Both winters resulted in extensive ice dams, despite calcium chloride use and roof raking.

I'm looking into self regulating de-icing cables, in the mid level offerings from Raychem (Gardian) and Emersion (Easy Heat PSR). Not planning on hardwiring until I see how they perform. Not exactly crazy about nailing the clips in every two feet into my brand new roof, but the Raychem online rep said using adhesive only would result in a mini-snow avalanche ripping the entire tab out.

Any experience? SE lower MI, in the tail end of the Lake Huron snow belt.

 

[RogueFab]

I'm about to install 400 feet of de ice cable under a lean to roof (metal). I'm not going to have it set automatic though. Not enough ice here. The roof isn't up yet btw. I. An let you know how it works after we get some snow if it helps...

 

[Rookie2]

easy heat uses aluminum push on clips, not very durable but after a few you figure it out . they make a temp/ moisture switch box to control the heat cable or you can just buy a temperature switch for $15.00.

 

[cybrdyke]

I LOVE my cables!!! I've had roof/ice problems in the past that resulted in expensive repairs. Some parts of my roof were poorly designed and are too flat, so snow piles up high, then freezes.
I have installed the cables all around. I plug them in only when I need to, usually right when it starts snowing hard. No regulators or automation at all. They work GREAT! The clips aren't nailed in at all. I have little aluminum clips with sharp teeth on them that bite right onto the shingles. Only once in a while does one come loose.
I think the secret to the system is to have one cable running the length of the gutter and downspouts as well as the zig zag pattern on the rooftop.
Two thumbs up!
CD

 

[cjn1014]

I LOVE my cables!!! I've had roof/ice problems in the past that resulted in expensive repairs. Some parts of my roof were poorly designed and are too flat, so snow piles up high, then freezes.
I have installed the cables all around. I plug them in only when I need to, usually right when it starts snowing hard. No regulators or automation at all. They work GREAT! The clips aren't nailed in at all. I have little aluminum clips with sharp teeth on them that bite right onto the shingles. Only once in a while does one come loose.
I think the secret to the system is to have one cable running the length of the gutter and downspouts as well as the zig zag pattern on the rooftop.
Two thumbs up!
CD

where are you located, and how bad was your ice dam situation prior to install?

 

[cybrdyke]

N.E. Ohio, in the snow belt. Ice would dam up on all the roof edges, but more so on the less pitched roofs.
How bad was it? I spent $4000 to have an entire exterior wall replaced.
CD

 

[justin1795]

I have a valley that I need to do this to.

 

[sands35]

Assuming you have a "traditional" construction home with an insulated ceiling, a pitched roof with proper ventilation.

If you are getting ice damns, that means the vented attic space is too hot. I'd suggest that there is either:

* Inadequate insulation on the ceiling.
* An air leak through a top plate or rim joist.
* Poor ventilation in that section of the roof.
* Soffit vent is blocked.

I would get into the attic or crawl space with a can of expanding foam, pull back the insulation and foam up any holes in top plates. Electrical runs as well as plumbing runs. Then make sure you can see light through the soffit vents. Perhaps put some more insulation on the roof deck if there is room and open up the soffit vents a bit with DIY vent chutes with ~2" of air gap not, 1" air gap.

 

[CNGsaves]

^ ^ Most often THIS . . . . . poor insulation.

 

[justin1795]

he has the problem I do vaulted cielings with no acess

 

[cjn1014]

those using the simple clips, are you constantly playing with them, or are they good to go after installation?

 

[CNGsaves]

He has the problem I do vaulted ceilings with no acess.

There is always access when you have a Sawsall !!!! . .

 

[cybrdyke]

those using the simple clips, are you constantly playing with them, or are they good to go after installation?

for the most part, they're good to go. For any that have wiggled loose, I just straighten them up when I'm cleaning the gutters.

 

[Erampu]

If the roofer installed ice and water shield, you wouldn't have this problem. The more permanent solution is to remove the shingles in the affected area, peel back everything, right down to the wood, make sure any flashing is good, install a layer of ice and water shield to the entire area, then cover it with new shingles.

 

[cjn1014]

Roof was redone, have new ice and water shield now. No leaks, but want to prevent the same damage from happening again. Issue is due to melting snow in a sun washed area dropping down onto a constantly shaded area that tends to collect spindrifts of snow. No immediate void access.

 

[Rookie2]

those using the simple clips, are you constantly playing with them, or are they good to go after installation?

Yes they **** because they are aluminum and they 2x **** if you have old hard shingles. If I do any more I would use a dollop of silicone or roof cement under the tab around the clip.

BTW I found that there is a slightly more durable cable ( I think they are made by easy heat but not sure, It's been a few years) available thru electrical distributors.

 

[cjn1014]

Those are the psr cables, similar to the raychem I was describing. Self regulating, but need to be secured with nailed clip plates.

Trying to see if I can get away with the simple adks setup from Emerson.

 

[Erampu]

If that area has the ice and water shield, you shouldn't be encountering the same problem again. Forget the cables and the old roof problems. There's nothing to worry about.

 

[justin1795]

We ha a roof guy look at ours said it should have ice and water barrier per code but if we wanted to know for sure he could tear it off and redo it. Said it could be a one time thing. He suggested running tar down the middle

 

[volleyball]

Maybe too late but adding hi density foam board to the deck under the shingles would have helped. Also what might be mentioning is the melting snow from above. Is it really from the Sun? could be poor insulation up above.

 

[bzinsky]

There are online sites to rent thermal imaging cameras these days. Everybody should rent one and just walk around their house on a cold day.

 

[AirJunky]

I bought an existing house about 10 yrs ago. 3 stories, a 12/12 pitch roof. I'm not getting on top of this place to do anything. I've had ice jam up between 2 peaks in the past.... WTF the builder built the roof with such a valley in it is stupid. So now what I do is pick up a package of women's nylons, just the knee highs.
Then I fill them with snow melt. I can stand in the driveway & huck them up on the roof +30' above me. Then the ice never forms in that spot. I do that 2 or 3 times a winter & the ice never forms. Then in the spring, the first good rain storm I have women's nylons falling out of the rain gutters into the driveway.

 

[volleyball]

Do the neighbors believe they are from ice melting?
Do you use the stuff that won't corrode metal?

 

[AirJunky]

Do the neighbors believe they are from ice melting?
Do you use the stuff that won't corrode metal?

He he, yea, for some reason they believe it.

My roof is 3 tab. But you bring up a good point. I suppose it could eat nails & flashing up.