On the roof of a building among the trees, fall leaves gather in the fall. From here they are transported by wind and rain to the gutters. They slowly rot there, but they make it difficult for rainwater to run off the roof, as a result, metal gutters are exposed to faster corrosion. Large amounts of leaves can cause moisture in various elements of the building. This should be prevented either by frequent cleaning of the gutters of leaves, or by installing a metal mesh in the gutters. Leaves will be blown from the mesh by the wind.