What Causes Asphalt Shingles to Curl?

Look around your neighborhood. Chances are you’ll notice that most of the roofs have asphalt shingles. Four out of five homes in this country have asphalt shingles, making them the most popular roofing materials. In this article, we take a look at what asphalt shingles are, why they are a popular roofing material, as well as what causes them to curl.

Asphalt Shingles: What Are They?

Asphalt roofing shingles are multi-layered, consisting of a base mat, asphalt coating, and mineral granules. The base mat — made of organic material like cellulose fibers or inorganic material like glass fibers — is saturated and coated with asphalt. The asphalt surface is then covered with ceramic-coated opaque mineral granules. Asphalt shingles have evolved through the decades, with the first self-sealing shingles being introduced in 1953 and laminated shingles appearing in the 1970s. The 70s also saw asphalt shingles with a higher fire resistance rating.

Benefits of Asphalt Shingles

It’s easy to understand why asphalt shingles are a popular choice for homeowners —no other roofing material can match their degree of performance, convenience, and economy. Take a look!

  • Fire Resistance: Asphalt roofing products comply with ASTM International and/or Underwriters Laboratories (UL) standards for fire resistance.
  • Economical: Longevity and moderate cost of application lead to low life-cycle costs.
  • Application Ease: These are the easiest roofing products to install.
  • Style Adaptability: Because they are flexible, strong, and aesthetically pleasing, asphalt roof shingles complement virtually any architectural style and roof configuration.
  • Weather Resistance: Asphalt roofing products can stand up to sunlight, temperature extremes/fluctuations, wind, precipitation, and ice.
  • Minimal Maintenance: Requiring little or no upkeep, asphalt shingles are a homeowner’s dream

Note: You may be surprised to learn that asphalt roofing products are estimated to be a $12-billion-dollar industry* comprised of a variety of materials, including shingles, roll roofing, ply felt, built-up (BUR) systems, and underlayment.

*Asphalt: The magazine of the Asphalt Institute, The Basics of Asphalt Roofing

A Curl is a Shingles Way of Saying “Help”

As you scope out your neighborhood, you may also notice curled or buckled shingles — maybe even on your own roof. Although a curled shingle here or there might not seem like a big deal, don’t be fooled. Damaged shingles are a red flag, and a warning of an underlying problem — a problem you should not ignore. Curled shingles allow water to seep into your home’s structure, causing long-term damage, leading to mold infestations and decreased air quality in your home.

Why do Asphalt Shingles Curl?

Curled shingles are a reason for concern because they’re symptomatic of trouble elsewhere on the roof. Properly installed asphalt shingles will deliver years of reliable performance with little maintenance, but some conditions can impede the trouble-free performance you expect.

There are five primary reasons that asphalt shingles curl, leading to other problems including:

1. Under-ventilated Attic

Inadequate ventilation traps moisture and heat in the attic. Hot, moist air that is not removed can result in a variety of trouble spots: nails, flashing, duct straps may rust, and shingles may rot if water builds up underneath them. The result? Leaks, higher utility bills, and the formation of mold and mildew pose a health hazard to you and your family.

2. Poor Installation

If shingles are not applied according to the manufacturer’s instructions, problems may develop that compromise the material’s ability to perform. Also, if shingles absorb moisture before installation due to poor storage, leaks, and other serious issues can arise once the installation is complete.

3. Poor Quality Shingles

Unfortunately, the shingles themselves can be the problem. Flawed products due to substandard manufacturing practices are bound to fail. If this happens to your roof, be sure to have a reputable, licensed professional document the problem for warranty purposes.

4. Overlaid Material

Curling or buckling can result when shingles have been installed over the old roof, preventing them from sealing properly.

5. End of Shingle Lifecycle

Asphalt shingles may simply be showing their age. Even though most asphalt shingle roofs have a 15- to 30-year life span, the impact from severe weather, inadequate ventilation, extreme temperature variations, and other environmental impacts can damage shingles, shortening the life of your roof.

Even Roofs Need TLC

The best way to protect your asphalt roof is to be diligent about caring for it. Be sure to call a local roofing company for help when repair or replacement is beyond your capabilities. Be sure you choose a licensed, bonded, and insured roofing company for the best results. With an experienced, reputable roofing company in your area, you know your roof will be installed correctly according to the manufacturer’s instructions. Then, keep this roofing company on hand for routine, yearly inspections and maintenance.

Trust the experts at McKinnis

If you are in need of a roof inspection, roof replacement, or windows, siding, and gutter work, give us a call today at (866) 365-5056, visit our website at www.mckinnisinc.com, or fill out our contact form. Our Omaha roofing and exterior experts are highly trained and always ready to help!