Understanding the Natural Aging Process of Asphalt Shingles

Understanding the Natural Aging process of your Asphalt Shingle Roofing System

Asphalt shingles happen to be used on about four out of five homes in the United States, which does make them the leading choice in residential roofing which is not surprising with all of their advantages. Asphalt Shingles come in a wide range of colors, textures and are the most affordable. 

Most shingle manufactures offer a full line of asphalt shingles, which include 3-tab as well as architectural. Each type of shingle will undergo a natural aging process. 

The purpose of this article is to recognize the signs of asphalt shingle aging. 

It is natural for your roof to age and the aging process begins as soon as your roof is exposed to nature. The sun can raise rooftop temperatures as high as 60-70 degrees above the ambient temperature. Excessive heat and ultraviolet radiation from the sun can accelerate the aging of your shingles. Other things such as weather, walking on your roof and heavy snow can also contribute to your roof aging. Asphalt Shingles begin to age as soon as they are installed on your roof. Cracking, blisters, granule loss, buckling, curling and algae staining are all signs of aging. 

Shingle Curling

Curling is common in some shingles and is not a defect. It is natural for your asphalt to age and the layers to shrink with time. The shrinkage is what causes the edges of the shingles to curl.

*Photo shows aged Asphalt Shingles that have started to curl. 

Shingle Cracking

Minor shingle cracking may not be noticeable from the ground however you might spot them while hanging your Christmas lights. Hight heat from the sun often causes the protective oils in the shingles to deplete which will cause minor cracking. This is all normal weathering and is not cause for panic as long as your shingles are still shedding water. Severe cracks that penetrate through the roof should be repaired and or replaced. 

*Photo shows aged asphalt shingles which have started cracking. 

Shingle Blisters

Occasionally, naturally occurring small, circular raised areas which are known as blisters may appear on your roof. These can vary in size and may be open or closed. They most often occur due to the attic being under ventilated. Closed blisters are not a reason for concern as long as your shingles are still shedding water. In the event that these blisters are open you should have a roofing professional assess your roof condition right away to have the shingles repaired and or replaced. 

*Photo shows an asphalt shingle with multiple blisters. 

Algae Staining 

In moist or humid areas, you may notice dark brown or black patches that appear on your roof. These streaks result in a dirty roof and are usually more visible on lighter colored shingles. This is a natural occurrence, and the stain is caused by algae growth which does not affect the ability for your shingles to shed water. Algae should not be confused with moss or tree droppings which usually only cause localized discoloration. 

*Photo shows an Asphalt Shingle roof with algae staining. 

Granule Loss

Granules are used in the shingle manufacturing process, so some granule loss is common when your roof is first installed. There are some other factors which can cause more extensive granule loss such as foot traffic on your roof, hail, tree limbs, and weather. In the event that you notice that there is exposed asphalt on your roof due to granule loss you should have a professional roofer assess your roofing system right away to have the shingles repaired and or replaced. 

*Photo shows and asphalt shingle with extensive granule loss. 

Shingle Buckling

Shingle buckling is not technically a sign of roof aging but can occur months after installation. This can be caused from inadequate attic ventilation which tends to increase the moisture in the roof deck. Expansion and movement of the wood roof deck can lead to the shingles becoming buckled.

*Photo shows buckled shingles. 

Normal Aging


-Surface Cracking

-Closed Blisters

-Algae Stains

-Slight granule loss

Abnormal Aging (Roofing Professional Needed)

-Open Blisters

-Cracks visible through the fiberglass or organic mat

-Exposed asphalt due to granule loss

Shingles begin to age as soon as they are exposed to weather elements. All roofing and buildings experience aging factors differently so it can be difficult to know exactly how long your shingles will last. If you ever have a question about the condition of your roof, feel free to contact Middle Creek Roofing at 1-717-949-2414 and we would be happy to come out and complete a roof assessment. 

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