Which option is often a visible indicator of moisture issues in masonry structures?

Efflorescence serves as a visible indicator of moisture issues in masonry structures because it occurs when water dissolves soluble salts present in the masonry or mortar. As the water moves to the surface and evaporates, it leaves behind these salts, which manifest as a white, powdery residue. This phenomenon is a clear signal that moisture is present, possibly due to inadequate waterproofing, drainage issues, or leaks. Identifying efflorescence is important for home inspectors, as it can suggest underlying problems that may require further investigation or remediation to prevent more serious damage to the structure. Understanding efflorescence helps in assessing the overall health of masonry elements and ensuring that moisture control measures are appropriately implemented.