Fiberglass shingles are a popular roofing choice because they are durable and resistant to many common roof problems. However, like all roofing materials, they experience thermal movement, which is expansion and contraction due to temperature changes. This happens because the materials in the shingles and roof deck expand in heat and contract in cold, causing slight shifts. While some movement is normal, excessive expansion or contraction can cause shingles to buckle, crack, or loosen over time. If you notice any curling edges or gaps between shingles, that might be a sign that thermal movement is affecting your roof. A simple, safe DIY check involves inspecting your roof during warmer and cooler parts of the day or year to see if the shingles shift or develop any visual damage. Look for loosened nails or spaces under shingles but avoid walking on the roof unless properly trained and equipped.
If you observe signs of thermal movement or are unsure about the condition of your shingles, it’s best to call a professional roofer. They can assess whether the issue is due to thermal movement alone or if other factors, like poor installation or fastener problems, are contributing. When talking to a contractor, ask if the shingles used are designed to handle thermal expansion in your climate and whether they recommend any adjustments, such as improved nailing patterns or spacing. Also, inquire about the warranty implications—whether thermal movement damage might be covered and what steps ensure your warranty remains valid. Knowing these details upfront helps protect your investment and ensures your roof performs well through changing temperatures.