UNIQUE CANADIAN INNOVATION MELTS ICE ON ROOFTOPS
Aluminum extrusion is fit under shingles at the eaves and heated through a cable
Does your roof develop lots of ice in winter? If it does, there’s a Canadian innovation you might want to know about.
I installed this system in the fall on a roof that has regularly developed concerning levels of ice in the past, and I’ve been watching the performance this winter.
Just like regular electric rooftop de-icing cables, this system uses electricity. The difference is that it’s almost invisible and it uses less power.
Just about every roof in Canada forms at least a little ice each winter, and in many cases this is no issue at all.
But when ice gets to be more than a few inches thick over a large area, it can mean trouble.
It’s not so much the weight of the ice, though that can be an issue if the ice gets really thick.
The main problem is what happens when rooftop ice holds back rainwater and melting snow.
Most shingle roofs aren’t capable of keeping out standing pools of water and this is why too much ice can lead indirectly to roof leaks.
Why do some roofs develop damaging levels of ice and others don’t?
Significant levels of ice form only on roofs that have enough heat loss to be above freezing while the surrounding air is below freezing.
This too-warm roof melts snow which then refreezes when the water runs down onto the unheated eaves area.
Boosting attic insulation and ventilation is the best way to solve the rooftop ice problem, but it isn’t possible with some roof designs.
This is why some people install traditional roof heating cables. They’re not made to melt all the ice along the eaves, but rather just melt vertical drainage channels here and there through the ice, allowing water to drain off the roof so it can’t sneak down between layers of shingles.
The thing is, there are three drawbacks with traditional zigzag installations.
Besides not looking all that great, conventional heating cables use a fair amount of electricity because they zigzag back and forth along the eaves.
The cables are two or three times longer than the length of eaves they cover. You don’t need to have these cables plugged in all the time, but they do use a significant amount of juice while operating.
Exposed rooftop cables are also open to damage from wind or if snow slides down the roof.
When Canadian inventor Lorne Heise decided to tackle the rooftop icing problem, he used a different approach.
Instead of relying exclusively on cables to deliver heat, he began with an aluminum extrusion. It’s 5 1/2 inches wide and fits underneath the shingles at the eaves.
The edge of the extrusion is made to accept a single electrical cable that conducts heat upwards to where ice needs to be melted.
The amount of cable required is roughly a half to two-thirds less because it travels in a straight line (no zigzagging).
The cable economizes on electricity in another way.
Heise calls his system Edge Cutter, and instead of just running full blast all the time, the cable delivers more or less heat along its length depending on temperature at that spot.
If there’s an area with lots of ice, the cable heats with full power in that location. If there’s another area that’s getting warm from the sun at the same time, electricity use throttles back automatically. You can watch a video of my entire installation at BaileyLineRoad.com /roof-ice
Can warming just the bottom five inches of a roof really stop the formation of ice that normally extends higher than this?
Yes, surprisingly enough it’s working fine on the roof I’ve been watching, even though this roof normally develops ice 16 inches up from the edge of the eaves each winter.
Just another example of how Canadians are a pretty innovative bunch, especially when it comes to battling ice. Steve Maxwell enjoys the annual battle with winter. Sign up for his free newsletter at Bailey Line Road. com and get videos, articles and contest giveaways delivered to your inbox each Saturday morning.