Waterproofing your roof and gutters are probably the most important step in the roof installation process, this protects the materials your home was built with, as well as all the things you keep inside. Prevents damage to structure: Water and moisture which seeps through a leaky roof slowly corrode the steel angles and beams which support your home. Concrete too is porous and waterproofing of roof is required to prevent deterioration over time, originating with water. Typically, extensive waterproofing measures are applied during construction. Waterproofing can also be applied to existing buildings to solve problems as they arise.