Clay and slate shingles are most likely to deteriorate due to which reason?

Clay and slate shingles are susceptible to deterioration from multiple factors, primarily water damage and UV exposure, making the response that both answers are correct accurate.

Water damage can occur because, over time, water infiltrates the materials, especially if there are any cracks or imperfections that allow moisture to seep in. This trapped moisture can lead to various issues such as mold growth, structural weakening, and eventually, spalling of the shingles, where the surface flakes or breaks away.

UV exposure is another significant factor contributing to the deterioration of these shingles. Over time, ultraviolet rays from the sun can weaken the material, causing fading, brittleness, and overall degradation of the shingles' integrity. This leads to a reduction in their lifespan and effectiveness in protecting the underlying structure.

While wind stress can certainly affect roof materials, it is less significant in the context of clay and slate shingles compared to the pervasive effects of water and UV light exposure. Therefore, acknowledging both water damage and UV exposure as primary reasons for deterioration is essential for understanding the maintenance and longevity of clay and slate roofs.