There are various materials available for residential roofing, including asphalt shingles, tile, metal, and wood shake. However, most roof leaks do not result from faults with the top roofing materials. Instead, the primary source of roof leaks is problem flashings.
Flashings are metal or other materials used to cover and seal penetrations and intersections in a roof and often involve the meeting point of different materials. Penetrations are building elements that create holes in a roof through which pipes, vents, or chimneys go.
Since the builder made a hole in the roof, the roofers must place flashing over the gap between the pipe or chimney and the roof to prevent water from entering the gap. The flashing can be improperly installed, degrade or rust, or temperature changes can affect the materials differently so that water gets into the underlying roofing material or the house itself, leading to a roof repair.
The flashings at intersections also cause problems. Intersections are where roof slopes and walls meet, creating ridges or valleys. Roof ridges are less troublesome since water flows away from them, but water flows into the valleys, so they are more likely to remain wet and degrade. Knowing these are the problem spots, you should have your roof professionally inspected annually to spot and repair potential roofing problems.
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