
Quoting
Jean5720
If you have not owned a building with a metal roof in an area that gets lots of snow you do not understand the physics of snow coming off a pitched metal roof. In our area it is not uncommon to get 6 inches of heavy wet snow. Snow sticks to the metal roof until there is a bit of melting then the snow next to the roof melts and all the snow on the roof tends to slide off at one time. The neighbor's building has a roof with a significant pitch so the snow will slide off when there is a bit of melting. You never design a building here to allow the snow to fall off a roof infront of your garage door, because your garage door will be buried. The roof is approximately 35 feet long and 16 feet wide near my driveway. An equal amount of snow will fall on the other side of the building. 6 inches of heavy wet snow weighs, according to FEMA, 21 pounds per sqare foot. So 35 x 16 feet is 560 square feet at 21 lbs per square foot is 11,760 lbs of snow that will slide off the roof at one time when the roof heats up. That is just shy of 6 tons. It is not uncommon to get a foot or more of snow here at one time. That is 12 tons of snow that will fall off the roof at one time. We average over 100 inches of snow a year. The snow when it comes off the roof is usually very compacted and icy and wil and has crushed cars and killed people. Building a higer fence will not stop an avalanche of snow that will fall on my fence and drive way. This snow then freezes hard like a rock. The pile of snow that comes off will block my drive. The snow that falls, falls on the ground that is already has snow on it. It is a huge dangerous problem. If someone happens to drive by when the snow decides to slide off the roof, you can all of a sudden find yourself under tons of heavy icy snow. I am sure there are You Tube videos of snow coming off metal roofs that can help you understand the danger of the situation. It is very difficult here to find someone who will plow the snow that falls off the metal building unless they have really heavy equipment and that will damage my driveway.