Fire Damage to Shingles
On occasion we are called in to a situation where a building or home owner is concerned that the shingles on his/her roof were damaged by the heat from a nearby fire. Damage from exposure to excessive heat to shingles can usually be determined by a visual examination of the shingles and their comparison with shingles clearly not exposed to excessive heat from the fire.
In one case where it was obvious there was no heat damage, the method of visual examination did not convince the owner. In that case expensive laboratory tests were performed. These tests showed that no chemical or physical changes could be identified in the asphalt materials of the shingles. The shingles were just deteriorated from aging.
In this article we include shingles that we found had been damaged by exposure to excessive heat of the fire. In one case, we can see that the asphalt was heated to a point where it became somewhat liquid and it “flowed” down slope with granules in tack (Figure FDS-1).
In another case, we can see where a hot ember landed on the roof, heated a small area of asphalt, and the granules were washed off by the extinguishing waters (Figure FDS-2). The sharp edges and the smooth, but bubbled surface of the asphalt provide evidence of localized heat damage.
These are but a sample of heat damage to shingles and provide an idea of damage caused by exposure to excessive heat.