What You Need To Know About Thermal Splitting

Thermal splitting leads to cracked shingles that impact the ability of your roof to function. Being able to identify the cause of the splitting and making necessary repairs will keep your shingle roofing split-free for years to come. 

What Causes Thermal Splitting

At its core, thermal splitting is caused by shingle expansion that happens too rapidly. All shingles expand when they warm and contract when they cool, depending on the temperature outside. However, temperatures inside your home can impact your shingles too. 

Thermal splitting happens when this expansion affects different layers of a shingle more quickly than others. For example, the thinner underlayer of a shingle expands rapidly, while the outer layer of the shingle is cooler and slower to expand. This uneven heating will continually stress the outer layer of the shingle until it cracks and breaks.

It's difficult to identify a particular type of shingle that will fail, but thermal splitting is often a product issue. For example, thinner, cheaper shingles cannot distribute heat evenly and lead to splitting. Shingles made with organic materials tend to be able to absorb temperatures fluctuations more easily. 

Splitting can be an environmental issue and occurs in environments where there are rapid temperature changes. Rapid changes in climate don't allow enough time for shingle layers to recover between fluctuations in temperature. 

What Thermal Splitting Looks Like

To identify splitting, you can use binoculars to scope out your roof from the ground. Temperature fluctuations cause the shingles to tear in a variety of patterns. When you inspect your roof, you could see vertical cracking that looks like the shingle split in two. You may also see horizontal or curved cracks in your shingles. 

Typically with thermal splitting, these issues will occur in a localized area on your roof where the thermal expansion occurs. 

When You Need To Replace A Splitting Roof

Once you've identified that your roof has splitting problems, it's important to determine what needs to happen next. 

Minor cracks and splits are typically only a cosmetic problem for your roof. However, when the cracks and splits become widespread, it increases wind damage to your roof. Over time with increased wind damage, you'll lose shingles, or the cracks will spread to other portions of your roof.

This widespread cracking can wear away the waterproof layer of your roof. Once that layer wears away, it's time to look at a roof replacement. 

Regularly inspecting your attic, particularly after periods of rain, will help determine if the cracking is more than just cosmetic. If the thermal splitting has compromised your roof, you'll see evidence of water damage on the ceiling in your attic.

If you suspect thermal splitting is affecting your roof, reach out to a local roofing company. They will be able to make product recommendations and replace your splitting shingles.