Heat Impact on Asphalt Shingles

Asphalt shingles are a very common roofing material. They’re inexpensive, lightweight, relatively easy to replace, and have a reasonable lifespan. One of the things homeowners and property managers need to pay attention to in the summer is heat impact. How much damage can the sun and often high temperatures of the Pacific West Coast have on the shingles?

Over time, exposure to the elements will cause the shingles to deteriorate. Extreme heat and sun exposure can speed up this process, meaning you need to replace shingles or the whole roof earlier than the estimated roof life expectancy.

What are some of the signs that your shingles are experiencing heat damage?


When the shingles become dry and inflexible they are prone to cracking. Cracked shingles increase the risk of moisture getting below the shingles and into the roof structure.


Heat can also cause shingles to shrink. When this happens the nails holding the shingles to the roof can pop out. Blisters in the shingles form and when they pop they leave the asphalt unprotected and prone to increased degradation. As with most roofing damage they can also lead to leaks.

Damaged flashing

Metal flashing is more durable, however, if you have plastic flashing it can start to pull away, stretch, and break as the roof joist expand in the heat. When flashing is damaged it allows water to penetrate the roof and causes leaks and mold or mildew growth on the roof or the roof structure.

How can you prevent heat damage?

  1. Ensuring your roof is installed properly is the first step to ensuring your shingles don’t have extreme damage from heat.
  2. Another option is to install lighter colour shingles. Black shingles absorb heat and are more prone to damage. Installing lighter colour shingles reduces the heat absorbed and can give your shingles a longer life expectancy.
  3. Proper ventilation in your attic is also an important factor. Ventilation allows heat to escape from the roof instead of building up and causes damage from the inside.
  4. Regular roof inspections ensure that little issues do not become major issues. Often when damage is identified at an early stage it’s easy to replace single or small blocks of shingles. If things escalate it may require the whole roof to be replaced, which can be a large cost you were unprepared for.

Summer heat, followed by heavy fall rains can really wreak havoc on asphalt shingles if not maintained properly. Yearly roof inspections help prolong the life of your roof and can prepare you financially for any repair costs. They can also help you learn to identify potential problems and give you a better understanding of some of the things to be aware of.

To learn more about getting your roof inspected contact the Roof Tech team at +1.604.888.7663 or info@rooftechconsultants.ca