Synthetic slate roofing is designed to mimic natural slate in appearance but is made from composite materials, such as rubber, plastic, or polymer blends. Thermal movement refers to the expansion and contraction of these materials caused by temperature changes throughout the day and seasons. When synthetic slate heats up in the sun, it expands slightly, and as it cools, it contracts. This movement is natural and expected but can lead to issues like loose fasteners, warped panels, or small gaps if the installation doesn't allow enough room for this movement. Proper installation usually includes fasteners that permit some movement and appropriate spacing to accommodate thermal changes. Signs of thermal movement include visible gaps between tiles, slight buckling, or noises when the roof heats or cools, which can be spotted during a basic visual inspection from the ground with binoculars or safely on a ladder.
For a safe DIY check, look for tiles that don’t lie flat or areas where gaps seem to be opening or widening. If you safely access the roof, feel whether any tiles are loose by pressing gently on their edges—looseness could indicate thermal movement problems or fastening issues. When complaints of movement appear, or if gaps are large enough to let water through, calling a professional roofer with experience in synthetic slate is advisable. A contractor can assess if the fasteners need adjustment or if expansion joints should be added. Questions to ask include: “How do you account for thermal movement in synthetic slate during installation?” and “Do you use fasteners or clips that allow for expansion and contraction?” These will help ensure your roof is both durable and able to handle normal temperature-driven changes without compromising warranty coverage.