Snow guards are rooftop devices that allow snow and ice to drop off in small amounts or allow snow and ice to melt completely before falling to the ground. The installation of snow guards prevents the sudden release of snow and ice from a roof, which is known as a roof avalanche. A roof avalanche can cause damage to people, pets, cars, landscaping, gutters, plumbing vents, lower roof areas, skylights and anything else that might be in the immediate area below your roof. Snow guards have been around for hundreds of years and have historically been used on slate, tile and metal roofs.