When a roof has been exposed to a hailstorm severe enough to cause granules to be dislodged from the surface of the shingles (in spots large enough which expose the asphalt), the roof has been compromised.
The colored granules which are placed on the surface of the shingle serve two purposes:
- They provide an aesthetically pleasing product, and
- They protect the underlying asphalt from exposure to the sun.
Prolonged exposure to sun causes asphalt to deteriorate. This is the reason that a hail damaged roof will tend to fail prematurely.
Heavy hail damage is obvious because of the indentations in the shingle. When the surface damage of the shingle is not visible, look for indentations on vents, ridge vents, siding, or any other softer metal objects that may show impact.
The effects on the shingle may not be apparent for about a year. At this time, circular areas of granules will fall off the shingle. This is often called spalling. What has occurred is that the impact of the hailstone has broken or weakened the bond between the granules and the asphalt.
After a year or so of weathering, the granules fall off the shingle in the circular area of impact. With granules missing, the sunlight (UV) quickly attacks the asphalt and the maximum performance of the shingle has been compromised. The standard Limited Warranty on Roofing Shingles is void when shingles are damaged due to the evidence of hailstorms under all conditions stated above.