So I acquired a metal roof this summer from a near-bye building which was only about five years old and was being dismantled. My wife and I always wanted a green metal roof to go with our red barn and this one sort-of dropped into our hands ( it paid to ask a question). This fall we had it installed and my buddy who installed it for us added these snow guards. He warned me that snow builds up on metal roof, then lets loose and slides. These "stops" he installed will slow it and break it up as well, so it hopefully all doesn't come sliding down in one big kabooom! Now, we have but a few inches of snow on the ground up on the hill, but it was interesting to me to see these little heavy-duty guards do as they are intended. Our barn is not heated in any way, so the under side is as cold as the top side. Not sure if that is good or bad.
My buddy warned me to not slam the barn door and then walk out. Sudden vibration......kaboom..... avalanche.......Wisdom!