Which condition appears on many newer asbestos-cement products exposed to weathering?

Efflorescence is a condition that manifests as a white, powdery residue on the surface of asbestos-cement products exposed to weathering. This phenomenon occurs when water-soluble salts within the material dissolve in moisture and then migrate to the surface as the moisture evaporates. As the water leaves the material, it can leave behind these salts, resulting in the visible white coating known as efflorescence.

Newer asbestos-cement products are often designed for durability and resilience; however, exposure to moisture, particularly in environments with significant rainfall or humidity, can create conditions conducive to efflorescence. While other conditions such as mold growth, rust, and cracking can also occur on building materials, they are less characteristic of the impact of weathering specifically on asbestos-cement products compared to efflorescence.