No. 18
1999-05-10
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EXCESS ROOFING GRANULES ON SHINGLES

During the roofing manufacturing process, roofing granules are applied into the hot top coating asphalt. An excessive amount of granules is used to provide total and complete coverage of the asphalt. The asphalt must be completely covered to ensure protection from solar ultraviolet radiation.

The granules are "pressed" or embedded into the asphalt coating while it is still hot. Some of the excess granules may not be firmly embedded but are only loosely held in place on the roofing sheet. The roofing machine is designed to reclaim the excess "hitchhiker" granules and reuse them. However, some of the "hitchhiker" granules are packaged with the shingles in the finished bundle.

During the first two years of shingle exposure on the roof, the "hitchhiker" granules will come off the shingles and may be found in the gutters or at the bottom of downspouts. Loss of these excess "hitchhiker" granules is completely normal and in no way results in a reduction of the weatherproofing life of the shingles. Granule loss only becomes a concern for shingle performance when bare spots of coating asphalt are exposed on the surface of the shingles.

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