What is the primary function of granules on conventional or asphalt shingles?

The primary function of granules on conventional or asphalt shingles is to protect the shingles from UV rays. These granules act as a shield, preventing harmful ultraviolet radiation from degrading the asphalt base of the shingle, which can lead to premature aging and deterioration. By absorbing and reflecting UV radiation, the granules help prolong the life of the roof and maintain its integrity.

While granules do add aesthetic appeal and can influence the color of the shingles, their most critical role is related to the protection they provide from the elements, particularly UV rays. This protection is essential for ensuring that the shingles perform effectively over their expected lifespan.