When changing to a heavier roof-covering material, which type of cracking may occur on wall coverings?

Switching to a heavier roof-covering material can lead to compression cracking in wall coverings. This occurs because the increased weight from the roof puts additional stress on the underlying structural elements of the building, including the walls. As the load increases, the walls may begin to compress, leading to cracks typically found near the bottom or along the joints of the walls.

Compression cracking is characterized by cracks that form as a result of the structural elements being pressed together due to the added weight. This can challenge the integrity of the materials and potentially lead to further structural issues if not properly addressed.

Other forms of cracking such as shear, transverse, and expansion do not appropriately describe the stress and subsequent cracking that would occur from the increased weight of roof materials. Shear cracks typically occur due to lateral forces, expansion cracks are related to temperature fluctuations, and transverse cracks are often associated with bending or tension stresses, neither of which are the primary concern in the context of heavier roofing material being added.