The purpose of this article is to help you recognize the signs of asphalt shingle aging. By doing so, you’ll be able to distinguish between natural processes that are no cause for alarm and possible defects that do require attention and repair.
· Surface cracking
· Closed blisters
· Algae stains
· Slight granule loss
In Need of Repair
· Open blisters
· Cracks visible through the fiberglass or organic mat
· Exposed asphalt due to granule loss
It is natural for your roof to age. The process begins as soon as your shingles are installed—and exposed to the harsh elements of nature. The sun can raise rooftop temperatures as high as 50–70 degrees above ambient temperature, and the excessive heat will inevitably take its toll. Ultraviolet radiation from the sun has also been shown to degrade and accelerate the aging of the shingles’ asphalt layers. Other factors such as pollution, hail, snow loads, tree limbs and people walking on your roof also contribute to the natural aging process. Asphalt shingles will undergo accelerated aging during their first year on your roof. And while the process slows dramatically after this initial curing phase, the visible effects will become more noticeable over time. Minor curling, surface cracking, blisters, algae stains, granule loss and buckling are all signs of aging.
Curling is a common phenomenon in some shingles and is not a defect. It is natural for asphalt to age and asphalt layers to shrink with time. This shrinkage may result in the slight curling of the edges of the shingle.
While minor cracks may not be noticeable from the ground, you might spot them while hanging your Christmas lights. Intense heat from the sun often allows protective asphalt oils to deplete, causing minor cracks. Keep in mind that these normal weathering characteristics are not cause for alarm as long as your shingles are still providing the intended protection. Cracks that penetrate through the fiberglass or organic mat should be investigated.
Occasionally, naturally occurring small circular raised areas known as blisters may appear on your roof. These pockets may vary in size and be open (exposing the asphalt) or closed. Blisters are often a direct result of under ventilated attics or excessive use of plastic cement. Closed blisters are not reason for concern as long as your roof is providing the intended protection. However, open blisters do mean asphalt is exposed and immediate attention is required.
In moist, humid areas, dark brown or black patches may appear on roofs. These streaks result in a dirty ooftop, often more visible on lighter-colored shingles. This naturally occurring stain is caused by fungus growth and will not affect the protective qualities of your shingles. Algae discoloration should not be confused with moss or tree droppings, which typically produce only localized discoloration.
Since extra granules are used in the manufacturing process, some granule loss is to be expected during the early years of your roof. Other factors such as foot traffic, hail, snow or brushing tree limbs may cause loose granules. However, exposed asphalt due to granule loss is a reason for concern and warrants immediate attention.
While not technically a sign of aging, a distortion of shingles known as buckling can occur months after original application. Lack of adequate attic ventilation can increase the moisture content of the decking material. This may cause expansion and movement of the wood deck to buckle shingles.