Roof damage can be caused by many different things as the years pass. For example, mildew growth, algae growth, direct sunlight, extreme weather, and other things can all provide challenges to roofs, and can harm them over time. Hail is one thing in particular that causes a lot of damage to roofs. In some hailstorms, the hailstones are as large as golf balls. So, when they fall from the sky and land on roofs, it can cause a lot of damage.