Asphalt Roof Granules: 4 FAQ

Asphalt shingle roofs are the most common roofs in the country. If you have an asphalt shingle roof or have considered installing one, then you may wonder why asphalt shingles are covered in granules and have many questions about these granules.

Read on to learn the answers to four frequently asked questions (FAQs) about asphalt shingle granules.

While the exact composition of asphalt shingle granules can vary depending on the shingle manufacturer, these granules are typically made up of a combination crushed stones and minerals.

Your shingle granules serve many important purposes. These granules are pigmented to provide your shingles their attractive color. While most shingles only have one shade of granules, dimensional shingles are often covered in several shades of granules mixed together to enhance visual appeal.

However, shingles are not covered in these granules for aesthetic purposes alone. Shingle granules also reflect the sun's heat and UV rays to protect shingles from heat damage and prevent shingle heat absorption. When shingles absorb less of the sun's heat, they tend to pass less heat into the air of your home during the summer. In addition, these granules also increase the fire resistance of your roof.

If you notice that asphalt shingle granules have fallen off your roof shortly after installation, you may wonder if this signals a shingle defect or other problem. You may find these granules in your gutters after it rains or on the ground surrounding your roof for a short period of time after shingle installation.

Not only is it normal for granules to fall off your roof shortly after shingle installation, but this granule loss is actually expected.

Shingles typically have both embedded and non-embedded granules. While the embedded granules are intended to stay attached to the shingles, the non-embedded granules are added to help protect the shingles and embedded granules during installation. Non-embedded granules should rinse away from the rain after installation.

Thermal cycling, which is the natural daily fluctuation in temperature, causes shingles to slightly expand and contract, leading to granule loss or loosening. Heavy rains and winds can further loosen granules and rinse them away. Heavy hailstones can immediately loosen and remove roof granules as they hit the roof surface.

While granule loss is a normal part of the roof aging process, your roof does lose some of its ability to reflect the sun's heat and UV rays. Also, your roof may begin to lose its radiant color as granules wear away.

Unfortunately, you cannot avoid all shingle granule loss, since you cannot control the weather.

However, you can take these steps to prevent granule loss:

• Avoid walking on your roof more than necessary. Foot traffic can place additional wear and tear on shingle granules.
• Remove tree limbs that hang over your roof. These limbs can brush against your roof surface and loosen or remove granules. 
• Have an experienced professional clean your roof. Many homeowners remove roof granules when cleaning their roofs too harshly. A professional can clean your roof thoroughly yet gently enough to remove few granules.

Also, take steps to keep local wildlife off your roof, if possible, to avoid excess granule loss.

If you have an asphalt shingle roof or plan to install one, now you know the answers to many of your questions about asphalt roof granules. Contact the roofing experts at Alton Roofing Services for expert roof shingle replacement today.