Eavestrough-snow-standing seam roof
We are nearing the completion of our owner built ICF home and at the decision point of options regarding eaves-trough retention when the snow slides over the winter months. The roof is 24 ga metal standing seam 8/12 pitch and we are subject to significant snow accumulations occasionally in the BC Okanagan. The building code here requires eaves-troughs and roof water drainage plan. I have a rain water collection tank in the works as we are on a well in a semi arid region during the summer months.
Standard gutters will get mangled/torn off when the heavy wet snow hits and slides. The options I am aware of are stick on or screw snow stops, screw or clamp on snow bars with a conventional eave-trough. Another route through my local roofing supplier is a European style heavy gauge metal eaves-trough kit with what look to me like robust hangers, parts and the price to go with it. Any other options out there that I am missing?
I an not keen on anything that puts a hole through the roof to secure. I don’t like the look of the snow stops or bars so the Euro style is what I’m leaning towards. Any other suggestions would be appreciated? I have attached a photo as well for clarity.
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I would lean towards some form of snow retention. When a large snow lets go on a metal roof and falls to the ground, it sounds like a multicar collision just outside your window. I've tried no snow retention and installed it after a year.
In the northern Ontario, roofs like yours would have a piece of bent triangular flashing screwed to the bumps of the panels all the way across the bottom. I find it adds a nice line to the roof.
If you don't want snow guards, there are surface tension based gutter guards that would allow the snow to slide off the roof without getting stuck. The nice part about those is you can inset your gutters a fair bit under the roof for a clean look. Don't know how well they work, just seen them used.
I have had success installing the gutters at a height where moving snow and ice shoots over the top of the gutter but water falls into it. That might be hard to do with an 8/12 roof and long runs are difficult to slope enough. You're going to have a hard time keeping snow on that slope.
I am pretty sure we ran a Q&A spotlight regarding locating gutters in such a way that they catch water while letting released snow scream by...but I just searched and could not find it. It was even one I wrapped up...
But I do remember that when I searched locally (southern VT) I found two "high performance" gutter installation companies, who were not cheap and only installed heavier gauge, more expensive gutters, but they convinced me that they understood the issues at hand.
The first time I replaced gutters dangling from a metal roof 8/12 slope I thought the original installation was cheap and shoddy. A wire was wound around a nail 6 or 8 inches up the roof and then down around an old galvanized gutter and twisted together. The following year the gutters I had screwed solidly to the fascia were still firmly attached to the fascia which was either on the ground or still hanging on by one end. I have since discovered flexible metal strap hangers which allow the gutter to deflect harmlessly out of the way when the inevitable avalanche happens.