What is the primary concern regarding deteriorating clay and slate shingles?

Deteriorating clay and slate shingles raises significant concerns primarily due to their susceptibility to moisture retention and potential weight issues. Clay and slate are both heavy materials, and when they begin to deteriorate, they can absorb moisture, which can exacerbate their weight and lead to structural problems.

When moisture seeps into the shingles, it can lead to deterioration through freezing and thawing cycles, ultimately compromising the integrity of the roof. This moisture retention can cause issues such as mold growth, degradation of underlying structures, and increased load stress on the roof support system.

Moreover, the weight of deteriorating shingles can pose additional challenges. If the shingles become saturated with water, they increase in weight, which can exceed the load-bearing capacity of the roof structure, especially if the roof has not been designed to accommodate such weight. This can lead to sagging, structural failure, or necessitate costly repairs.

Considering both these concerns is crucial for proper roof maintenance and safety assessment, making the answer that encompasses both of these significant issues the most appropriate choice.