How Important Is Asphalt Granule Loss?

The shingles we lay on our roofs – and very likely soon forget – about consist of three layers. First, there a base that gives them substance. Next, there’s a waterproof layer of asphalt, and finally there’s a top coating of granules. While these granules do help prevent the shingles sticking together in stacks, they actually have a more important role.

Why Asphalt Granule Loss is Important

It’s quite normal to shed a few loose surface granules from a new roof. However, after that they should settle down to reflecting solar energy back, while adding the characteristic tint we chose so carefully. However, if the volume of granules at the bottom of the down pipes starts increasing then that could be another matter.

A steady increase in asphalt granule loss is an important warning sign. It could mean the asphalt roof is reaching the end of its lifetime, because the granule defence is failing. Hail or debris blowing a gale could damage the softer asphalt underlay to the extent a few shingles could fail as in our photo.

How to Go About Choosing New Shingles

There are two broad types of shingles, namely those with a biodegradable organic base, and those using the artificial material fibreglass. Both have an asphalt layer on one side impregnated with the important granules.

Those small particles may be slate, schist, quartz, vitrified brick, stone, or ceramic material. Some may also have a biocide added to help deter algae growth. All asphalt shingles have self-sealing strip on the underside to resist upper pressure of high winds.

The Difference Between Architectural and Three Tab Shingles

Excessive asphalt granule loss is an important indicator of an aging roof. The other factor to consider is the design of the shingle itself.

1… Standard, three-tab shingles are simple flat shapes of uniform appearance. They are less expensive because they use minimal material. However, this means they have a relatively short life of 12 – 15 years.

2… Architectural shingles, on the other hand are thicker and stronger, and therefore cost more. They create a more varied texture because they vary in shape and size, and may last ten years longer.

Which Type of Shingle Is Best for My House?

Let’s turn the question around and ask, how long do you want your roof to last? Always ask a developer about their shingles before you purchase a new home. If you are re-roofing an old house and are planning to settle down, then architectural shingles will stay looking good longer, and that’s one less thing to worry about.

More Information

A Good Roof Is More Than a Low Price

6 Ways to Spot Shingle Hailstone Damage

Ask Valiant Exteriors for Impartial Advice

Image: Storm Damage to Aging Asphalt Shingles: Samuel Bolton BY CC 4.0

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