Polyurethane roof coatings are popular for their durability and waterproofing qualities, but like many roofing materials, they can suffer from UV degradation over time. Ultraviolet rays from the sun break down the chemical bonds in the coating, causing it to become brittle, crack, or chalk. This process reduces the coating's effectiveness, allowing water to seep in and potentially damaging the underlying roof structure. The main cause of UV degradation is prolonged exposure to sunlight without adequate UV protection in the coating. Simple diagnostics include visually inspecting the roof surface for cracking, chalking (a powdery residue), or fading. Another safe way to check is by gently running your hand over the surface to feel for rough or brittle patches that weren’t there before. If you spot damage early, you can often extend the coating’s life with cleaning and spot repairs.
If you notice signs of UV damage, it's wise to consult a professional roofer, especially if the cracks or chalking are widespread. A reputable contractor can evaluate whether a recoating or a full roof replacement is necessary. When choosing a contractor, ask how they handle UV degradation and what types of polyurethane products they recommend for your climate. It’s important to confirm if the coating they use is compatible with your existing roof system and whether it maintains your warranty. Another key question is how long the product's UV resistance is guaranteed. Taking these steps helps protect your investment and ensures your roof performs well under the sun’s harsh rays.