Oil canning is a visible waviness or rippling effect often seen on metal roofs, including those with silicone roof coatings. It happens due to uneven tension in the metal panels, thermal expansion and contraction, or poor installation practices like inadequate fastening or panel alignment. When silicone coatings are applied, they can sometimes highlight these imperfections rather than hide them, especially if the underlying metal already has stress points or if the coating is too thick in some areas. You can usually spot oil canning by looking at the roof from a low angle and noticing irregular waves or dents that distort the surface's smoothness. A simple DIY check is to inspect the roof under different lighting conditions and observe any visible ripples. Also, gently press on areas with noticeable waviness to check for panel movement. However, avoid walking on the roof too much to prevent damage to the coating.
If you notice oil canning on your silicone-coated roof, it’s a good idea to call a professional roofer who specializes in metal roofing and coatings. They can diagnose whether the problem is due to panel installation, substrate movement, or coating application issues. When consulting a contractor, ask questions like: “What steps will you take to correct or minimize oil canning without affecting the coating warranty?” and “How will you ensure the silicone coating is applied evenly to prevent further visual or functional issues?” Proper fixes might involve re-securing or replacing panels, adding stiffening ribs, or carefully recoating to maintain the roof’s protective qualities. Remember that addressing oil canning early helps avoid bigger problems like water infiltration or coating failure down the line, keeping your roof both durable and visually appealing.