What Does Degranulation Mean for a Roof
Granules are the outer shield of asphalt roofing products. They protect the asphalt layer underneath from sun exposure and physical wear. Because granules serve as an asphalt roof’s protective outer layer, the extent of degranulation is often evaluated in roof inspections to determine the age and remaining life of a roof.
When granules are knocked loose by hail or worn away with age, the exposed asphalt dries faster and the shingle loses durability. Localized granule loss at a bald spot may indicate hail damage, while widespread thinning across the roof usually points to age or long-term weathering.
When degranulation occurs, homeowners are likely to notice granules below their downspouts or inside of their gutters after rain.