What should be checked by pressing on clay or slate shingles during an inspection?

When pressing on clay or slate shingles during an inspection, the primary concern is to assess the movement of the shingles. These types of roofing materials can be brittle and are more susceptible to cracking or damage if they are not properly secured or if they have been subjected to movement due to structural settling, weather conditions, or other environmental factors.

By checking for movement, an inspector can determine if the shingles are loose, misaligned, or if there’s an underlying issue with the roofing structure that needs to be addressed. Movement can indicate that the shingles are not providing the necessary integrity and water resistance, which are crucial for the roof's overall effectiveness.

While examining for color fading, cracks, or the materials used is also important, these aspects are typically assessed visually and through other inspection techniques rather than through the pressing method, which is specifically aimed at evaluating the physical stability and attachment of the shingles.