What does the presence of moss on roofs indicate?

The presence of moss on roofs is a strong indicator of high moisture levels. Moss thrives in moist, shaded environments, often growing in areas where the roof does not receive adequate sunlight. This can be particularly problematic as moss retains water, which can lead to further moisture accumulation on the roof's surface. This excess moisture can contribute to deterioration of roofing materials, promote mold growth, and create conditions favorable for leaks.

In contrast, low humidity would not support the growth of moss, as it typically requires a certain level of moisture in the air and on the roof itself to thrive. High wind conditions do not create a favorable environment for moss, as windy conditions can dry out surfaces and disrupt the growth of such organisms. Lastly, cooling issues are unrelated to moss growth, as they pertain more to temperature management in living spaces rather than environmental factors that facilitate the growth of moisture-loving plants like moss.