Granular Retention: How to Make Roof Shingles Last Longer

granular retention roof shingles
I’m willing to bet that you didn’t even know that granular retention was a thing you want in your life, did you? Since you didn’t know, but definitely want it, let me explain so you at least know why.

What is Granular Retention?

Granular retention is the concept that the shingles on your roof should hold on to, or retain, the granules that are embedded on them. These granules play a crucial role in the overall roofing system for three main reasons:
  1. They provide protection to the asphalt layer of the shingles from UV rays.
  2. They provide fire resistance.
  3. They provide the aesthetic appearance (color) of the roof.
Those are three pretty big reasons for wanting the granules to stay on the shingle!

Granules and Shingle Health

During the manufacturing process, producers apply up to 40% more granules to the shingles than are necessary. Because of the overload, it is estimated that 12% - 15% of the granules do not fully adhere to the shingle, which results in granular loss before the shingle ever makes it to your roof. This shows that granular loss does not always indicate damage; the presence of loose granules simply means weathering has occurred. And granules are meant to be shed over the useful life cycle of asphalt shingles. So you shouldn’t be alarmed when you see some granules in your gutters occasionally - especially right after having a new roof installed. Below the granules, the asphalt layer of the shingle will disintegrate quickly without protection from the UV rays of the sun. This will result in an accelerated rate of wear on the roof, as exposed shingle substrate will start to absorb moisture quicker than shingles with granular protection. To add value to their product, most shingle manufacturers have already or are currently developing technology to stop premature shedding of granules - a.k.a. granular retention technology. See, I told you (that you had granular retention)!

When Shedding Granules is a Problem

Despite efforts by manufacturers to slow the natural loosening of granules over time, there are some other factors that can cause a rapid, problematic release of granules. These factors would cause severe enough damage that it would warrant action by the homeowner to repair the roof - widespread issues across the entire roof could even require roof replacement. The main reasons for this would include hail damage and a defective roofing product. But the potential problems are too numerous to mention here, and none are risking if you can avoid it (which you can, by having your roof regularly inspected and maintained). Long story short: you shouldn’t be surprised to see a slow, gradual loss of the granules on your roof. But you should be alarmed if you see the white fiberglass peeking through, if you see widespread granule loss, or if you see cracking, blistering or any other obvious damage to the shingles.

What to Do If You Spot Problems

If you notice damage to shingles or a large amount of granules that have come loose, contact the Roof Doctor. We’ll come out and inspect your roof and give you a clear idea of what your options are. Our team works hard to keep your roof in its best condition!
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