Roof & Gutter Heat Cables ?? OT

[Rich Carlstedt]

Living in Green Bay gives one a real perspective of Winter and Ice Some of the comments made are "generally" applicable and others may not.
Heat cables burn out when they are allowed to touch each other, so you must use separators. These are aluminum strips 1/32 x 1/2" wide and maybe 2 inches long that are rolled
on each end holding the cables apart, but parallel to each other and the aluminum acts as a conveyor of heat AND water between the cables . I have used cables here in Green Bay for 30 years and have 12 inches of insulation in the ceilings , but we get - 20 F temps and weeks where 10 degrees is a hot spell ......back to the cables. I have never had a burned out cable but I do replace them after 12 to 15 years because having a failure in winter is a real no-no. The cables only are effective from 20 to 40 F IMHO -----They shut off when it gets warm and when it gets too cold , there isn't enough heat. at 3 watts per per foot which is about 10 BTU per foot . My House was L shaped by design but I had the builder add my shop, and it became U shaped.
Two things work creating Ice Dams
The low angle of the sun means part of my roofs never see sunlight in the winter and the builder put the high efficiency furnace exhaust in the U , which means a heat + humidity source adding to the problem. I have 160 feet of cable (100 +60) and "W"s on the roof 3 feet high and a Valley . I start the cable 4 to 5 feet underground (drain field) ( 40 inch normal frost line ) on both down down spouts and the longer cable does the W's and the shorter is the valley and the gutter . The center of the "U" has two cables side by side , so water can go to either downspout.
This is Green Bay, so the rubber membrane covers 6 feet from the gutter besides having felt under the asphalt shingles . When my roof was redone a few years ago, I gave the roofer a dozen strips of aluminum 1/32 x 1" x 12 inches , and had him nail it under a course of shingles 3 feet up and 3 feet apart with a 2 inch exposure. Then I did my W's and used the strip by rolling then up a bit into C's .. before that, the cables came with shingle clips, and they eventually break or shred the bottoms of the shingles from expansion and contraction and you loose the W .

Hope this helps
Rich

[Doozer]

Down here in the land of Bless your Heart and Barbecue, I built my shop with a 4-12 pitch.
Balloon frame, I have 9 foot ceilings in the shop proper, and an attic with 4 foot knee walls
and 7 foot under the collar ties. The high bay has no attic, and 15' under the collar ties.
A traditional yankee land roof really would not have gained me anything, the way I layed
things out. A side note, I would never do a tin roof again. Can't walk on it without denting
it and it is slippery as heII. Asphalt shingles are way better and easier in my book.
It was a happy day when I sold my snow blower, I will tell you that. Yall's don't need no
heat tape 'round these parts ! ! ! ! !

--Doozer

[nickel-city-fab]

Imagine putting a steep roof on a Walmart, or the local GM factory. It would look like the Kremlin.

[Ridgerunner]

Save the planet by heating your roof. Why can't people just build houses with steep enough roofs so that the snow just slides off?

Money. It takes more material to build a steeper roof. More lumber and more roofing material. More siding, bricks, etc material to finish the gable ends too. In addition more labor. It is relatively easy to nail shingles or other material on a 4/12 roof from above. For a 9/12 or steeper roof it takes roof brackets and planks and working from below slowly nailing the shingles.

[nickel-city-fab]

The only roof that snow "just slides off" is a copper-plated church spire. In my part of the world, (Buffalo NY area) we are known for our snow, and the building codes all specify how a roof must be done to withstand the weight. Same for the depth of foundations, the legal minimum here is 5 feet, because that's how far the ground freezes.

[PS4steam]

Save the planet by heating your roof. Why can't people just build houses with steep enough roofs so that the snow just slides off?

I have 12 - 12 pitch roof and currently have about foot of snow on it, what pitch have you had actual experience with that works ie "just slides off" ? and what was the roof material?

[JoeLee]

I know the cold roof solution is not always possible but it is a very simple and relatively cheap permanent solution. I would explore the cold roof details a bit closer as it sounds like you do not have enough air coming in at the soffits. There are formulas for the vent areas square footage that must be met. Valleys may limit your total air input and those heating pipes may have some effect like you said. There are other solutions that will be permanent like foam sprayed in the attic space. It is not in your favor that you have a new roof as doing the job right may entail removing some roof panels to spray the foam. I would explore building solutions in cold climates to see if there are any good scenarios you could adapt to your particular situation. I have seen the foam done in one remodel and it was a combination of closed and open with results that were extremely good. No ice dams at all on that one. The joke was you could heat the place with a candle The reality is it was not cheap or easy.

I have all the air circulation I can get with soffit and ridge vents, aside from installing some type of power vent / fan to help draw in more cold air.

The thing that I don't get is the guy down the street from me has radiant heat in his ceilings through out his whole house and he doesn't have an ice problem.
My radiant heat is in the floor where it should be for efficiency reasons. I never did understand the concept of putting it in the ceiling. Heat rises !

JL..................

[JoeLee]

Here in CT we get ice dams occasionally. The most serious was in 2011 when several buildings in town collapsed from the snow load. Walmart used a snow blower to clear their roof, the only time I've seen that done.

In researching what to do about the ice dam on our roof in 2011 I ran across a document from the Canadian government which described useful things people did during the "Great Canadian Ice Storm of 1998". One suggestion was to get a heat cable and a wood 1x3; form 2' to 3' loops of heat cable along the length of the 1x3. Toss the 1x3 behind the ice dam with the loops hanging over the gutter. I did this and over night the cable cut 1/2" wide channels in the ice dam, allowing the water to drain. Once the snow melted I removed the setup and stored the tape for future use - thankfully it hasn't been needed again yet... So, if you're in a location where Ice dams occur only occasionally you might consider this.

Also, prior to 2011 I hadn't heard of a "snow rake" but they were suddenly popular - and suddenly VERY expensive - when this unusual weather occurred. We bought one the following summer when the excitement (and price) had died down -- and haven't opened the box, yet. It's a lot safer and easier than climbing on the roof to remove snow.

John

That's a pretty good idea........ I think I'll try that. This avoids the permanent installation issue. I could put them up in the late fall and plug them in when needed.
Throw them up on the roof in my two worst problem areas and see what happens. I could do it now if I wanted to but were supposed to be getting temps around 40 deg. this week so that should melt most of the snow off the roof and open up the ice dams.
For me, before ice damming doesn't become a problem until I get about a foot of snow or more on the roof with no thawing days for an extended period of time.
Glad I started this post. I knew I'd get some useful idea here.

TNX............. JL................

[Mike279]

I know the cold roof solution is not always possible but it is a very simple and relatively cheap permanent solution. I would explore the cold roof details a bit closer as it sounds like you do not have enough air coming in at the soffits. There are formulas for the vent areas square footage that must be met. Valleys may limit your total air input and those heating pipes may have some effect like you said. There are other solutions that will be permanent like foam sprayed in the attic space. It is not in your favor that you have a new roof as doing the job right may entail removing some roof panels to spray the foam. I would explore building solutions in cold climates to see if there are any good scenarios you could adapt to your particular situation. I have seen the foam done in one remodel and it was a combination of closed and open with results that were extremely good. No ice dams at all on that one. The joke was you could heat the place with a candle The reality is it was not cheap or easy.

[nickel-city-fab]

I used to work in the industrial valve industry.
Lots of valves got sold to process chemical plants around Buffalo NY.
Linde / Union Carbide, Ashland Oil, big customers.
We sold Raychem heat cables and their hot melt shrink tube termination kits.
Raychem use slightly conductive plastic/rubber between the conductors
to generate heat from resistance.
Just cut to length, and no need to loop the circuit.
-Doozer

Thx for the tip -- my old employer used to use them. Too bad most of us don't have corporate credit accounts.

[RMinMN]

Here in CT we get ice dams occasionally. The most serious was in 2011 when several buildings in town collapsed from the snow load. Walmart used a snow blower to clear their roof, the only time I've seen that done.

In researching what to do about the ice dam on our roof in 2011 I ran across a document from the Canadian government which described useful things people did during the "Great Canadian Ice Storm of 1998". One suggestion was to get a heat cable and a wood 1x3; form 2' to 3' loops of heat cable along the length of the 1x3. Toss the 1x3 behind the ice dam with the loops hanging over the gutter. I did this and over night the cable cut 1/2" wide channels in the ice dam, allowing the water to drain. Once the snow melted I removed the setup and stored the tape for future use - thankfully it hasn't been needed again yet... So, if you're in a location where Ice dams occur only occasionally you might consider this.

Also, prior to 2011 I hadn't heard of a "snow rake" but they were suddenly popular - and suddenly VERY expensive - when this unusual weather occurred. We bought one the following summer when the excitement (and price) had died down -- and haven't opened the box, yet. It's a lot safer and easier than climbing on the roof to remove snow.

John

I have used a snow rake on my outbuildings, all with metal roofs. I found muscles I didn't know I had the next few days as I would have to lift that snow rake and pull down just a little part of the snow on the roof. Last winter we had a lot of heavy snow and instead of using the roof rake to rake the snow down, I beat the rake part out flat and pop-riveted it to the handle. Now I turn it on edge to cut into the snow, then pull it back and lay it flat to go under the snow and I can bring big chunks down a little and let them slide the rest of the way off the roof. somewhat like these but without the plastic slid part.

https://www.amazon.com/Avalanche-Original-Removal-System-inches/dp/B002TLSTH4/ref=asc_df_B002TLSTH4/?tag=hyprod-20&linkCode=df0&hvadid=430970923360&hvpos=&hvnetw=g&hvrand=2118811613499209412&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9020241&hvtargid=pla-571233396178&psc=1&tag=&ref=&adgrpid=97423207182&hvpone=&hvptwo=&hvadid=430970923360&hvpos=&hvnetw=g&hvrand=2118811613499209412&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9020241&hvtargid=pla-571233396178

[GadgetBuilder]

Here in CT we get ice dams occasionally. The most serious was in 2011 when several buildings in town collapsed from the snow load. Walmart used a snow blower to clear their roof, the only time I've seen that done.

In researching what to do about the ice dam on our roof in 2011 I ran across a document from the Canadian government which described useful things people did during the "Great Canadian Ice Storm of 1998". One suggestion was to get a heat cable and a wood 1x3; form 2' to 3' loops of heat cable along the length of the 1x3. Toss the 1x3 behind the ice dam with the loops hanging over the gutter. I did this and over night the cable cut 1/2" wide channels in the ice dam, allowing the water to drain. Once the snow melted I removed the setup and stored the tape for future use - thankfully it hasn't been needed again yet... So, if you're in a location where Ice dams occur only occasionally you might consider this.

Also, prior to 2011 I hadn't heard of a "snow rake" but they were suddenly popular - and suddenly VERY expensive - when this unusual weather occurred. We bought one the following summer when the excitement (and price) had died down -- and haven't opened the box, yet. It's a lot safer and easier than climbing on the roof to remove snow.

John

[JoeLee]

Tar paper is not waterproof. It slows the entry but doesn't stop it. In some cities the use of a rubber membrane (which is much more expensive than tar paper) is required for the first 3 feet from the edge of the roof. Even then, nailing the shingles will poke holes in the membrane.

This is the stuff they use around the edges of roof lines now. https://www.iko.com/na/learning-cent...ter-protector/ The roofer ran two rows of it when he did my roof. I told him I didn't like the idea of it and he should stick with one 3 ft. wide strip. This stuff has sticks right to the plywood. It's pretty sticky and gooey on the adhesive side and I doubt any water would leak around any nails. I should have told the roofers to run the ice and water over the entire roof. Then it would have been 100% sealed, like a rubber roof.

I had thought of insulating the attic roof, but that's a lot of interior attic to insulate.

JL.................

[JoeLee]

"...to keep water from backing up behind the ice dam and seeping under the shingles which would ruin the wall."

Don't they use tar paper under the shingles in northern climates? It is the first thing they put down on every roof I have ever done myself or seen done. For flat roofs they "mop" it together with hot pitch so it forms a water tight layer under whatever the upper surface is.

Yes, they use the felt paper under the shingles here, always have but now roofers are using this... https://www.owenscorning.com/en-us/r...s/titanium-udl

It's much lighter and stronger and it comes in 6' wider rolls vs the 3' felt paper. But when the water backs up to the over lap it'll run under it and drip inside somewhere.

I've never seen a roofer "hot mop" the seams of tar paper together. I'm sure it's been done on roofs with a known problem.

JL.............

[JoeLee]

About $150 a foot. Called a "snow belt" I think - not quite as complicated as the one in that link. This one seems pretty straightforward, somewhat like heated flashing. I was worried an ice dam would form above it, but that hasn't been the case despite many opportunities. Not quite sure why, I'm sure the builder explained it to me back when I was uncertain of whether to pay the cost.

If it ever does break, though, that'snot gonna be fun.

I guess this is why I've never seen nor heard of this stuff before. at that price 60 ft. would cost about $9000. Maybe in a commercial building but not for the average homeowner.

JL................