Causes of Asphalt Granule Loss

Asphalt roofing sheets first appeared in 1893, and are still common in asphalt roll roofing but with surface granules added. The original asphalt shingle roof tiles showed up in Calgary early last century, after Henry Reynolds of Grand Rapids, Michigan came up with the idea in 1903.

Shingles hit the big time after he cut the sheets into squares, and by 1939 factories were churning out billions a year. However by then the idea of adding granules to the surface to extend shingle life was embedded, and this considerably extended their life span.

The Main Causes of Asphalt Shingle Granule Loss

The granules have several useful purposes besides making the raw sheets easier to separate. Their reflective surface helps deflect ultra-violet light, while choosing the right colours creates a pleasant aesthetic effect.

However, perhaps more importantly the granules protect the soft bitumen coating from boots walking over, hail pelting down, storm driven debris striking, and so on. Hence, shingle loss is not just a nuisance blocking eavestroughs and down pipes. It’s a useful warning sign too.

What Shedding Asphalt Shingles May Tell Us

1… If your asphalt shingle roof is still new then you may expect to see surplus granules coming loose after the first few storms

2… Somebody with clumsy footsteps has been walking on your roof or dragging things over it. They may have broken or dislodged a few shingles too

3… A recent hailstorm was more destructive than you thought. You need to find someone to go up there and inspect

4… The granules may be coming loose as a result of the asphalt surface blistering due to poor attic ventilation trapping heat

5… Fair wear and tear is one of the commonest causes of gradual loss. The asphalt coating dries out and releases the protective shield

The Value of an Annual Asphalt Shingle Roof Inspection

Some asphalt granule loss is to be expected during the product life cycle, as explained. However, it may be a warning sign of something else, if it is excessive. The only way to know for sure is to go up on the roof and inspect.

This is a job for professionals that know what they are doing because it’s a long way to the ground. Why not give Calgary’s favourite roofers Valiant Exteriors a call on (403)829-1661 to arrange a roof inspection before winter sets in?

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Asphalt Shingles Past Their Use-By Date: Dale Mahalko BY CC 3.0