I live in a lake side home, in the mountains. Typically it snows here in the winter. We are not talking a few flakes or a few inches….we are talking about feet of snow.
My garage is adjacent to the stairs leading down to the house, from our parking lot. The garage has a 7/12 slope steel roof. One might believe not very much snow will stay on a slick roof which is so steep. I fell into this category, until I first saw several feet on top of the roof. Then I closed the door of the garage and witnessed the snow coming off the roof like a freight train, burying my stairs in several feet of snow.
My back having learned the lesson the hard way, I came up with what I thought would be a solution the following summer – I had steel snow brakes added to my roof to keep the snow on. These are pieces of steel trim which screw onto the high ribs of the roof steel, keeping the snow on the roof…..until the snow got so deep it ripped the screws out of the steel, sending snow, snow brakes and my gutters plunging onto the stairs.
My eldest step-son teaches physics, so I am sure he will be impressed by my having used the laws of physics in coming up with a better solution.
Keep in mind, the correct snow guard solution involves holding back thousands of pounds of snow and ice. Done right, the property and personal damages from sliding snow are eliminated, removing not only the problems of removal, but also the potential liability risk involved if a person was to be hit by such an avalanche.
Back to physics, the most efficient design is a pad style snow guard with a three to five inch wide forward (uphill) mounted flat face, with solid support struts and base. Other shaped configurations have found to not be efficient at retaining snow, which is their sole purpose.
For strength, the guards should be made of either 100% prime virgin grade UV stabilized polycarbonate or American made 304 Stainless Steel.
The manufacturer should be able to provide independent test results and replace the product, in the event of a failure. The only thing worse than having to purchase a snow retention system… is having to buy a second one to replace the first one.
Snow guard layout is critical to performance. The best value will come with a professionally designed layout. Most often, companies will quote far too few guards to properly do the job, in order to be the low bidder.
A reliable layout will have multiple staggered rows of guards, with each guarded mounted in the center of the valley between the high ribs of the steel. The most common layout mistake is to mount a row near the eaves and call it good. This gives sliding snow a chance to build up velocity and damage the guards and allows too much load on the lower roof section, potentially causing a structural failure of the entire roof.
Proper snow retention layouts equally distribute the snow load across the entire roof. They will have multiple rows and a staggered placement.
Also, and just as important, most steel roofs are designed with a snow load adjustment due to snow being able to slide off a slick surface. If your new pole building will have snow guards of any sort installed, it is essential this snow load factor be set to not incorporate this reduction.
Take it from me, the guy with the shovel and the sore back…if you are in snow country – put snow brakes on. But have someone design your roof system so they do what they are supposed to…and hang up your shovel.