The damaging agents and enemies to your roof can be numerous. Improper ventilation often traps moisture in the attic, leading to structural decay. Trees and landscaping that shade your roof tend to permit the growth of algae and moss. Over time, this may stain your roof and destroy your shingles and underlayment. If trees actually touch your roof, they may interfere with proper drainage or loosen and damage shingles. Weather exposure can also cause damage to your roof. The sun can make shingles brittle, causing them to break. Wind may dislodge shingles and force water underneath them. Moisture can pool and rot the surface, developing leaks that damage the interior of your home. Failure to perform preventative maintenance checks, may increase the likelihood of expensive repairs. For more information on roof damaging agents, contact a roofing specialist in your area.