What is the difference between solid masonry and cavity masonry?

• A. Solid masonry uses steel reinforcement; cavity masonry uses no reinforcement.
• B. Solid masonry has air gap between wythes; cavity has no air space.
• C. Both are identical in function and design.
• D. Solid masonry forms a single load-bearing wall; cavity masonry has an air space between wythes for insulation and moisture control.

Answer: (D)

The main distinction is the presence of an air space between masonry wythes in a cavity wall, which changes how the wall carries load and handles moisture and heat. In solid masonry, the wall is a single mass that bears the structural loads as one unit, with no gap to separate parts of the wall. In cavity masonry, there are two masonry walls (wythes) separated by an air cavity; the outer wythe resists weather and provides the exterior finish, while the inner wythe supports interior finishes, and the cavity allows insulation and moisture control. That air space acts as a buffer, improving thermal resistance and providing a drainage path to reduce moisture transfer, often with ties connecting the wythes and features like weep holes to manage any moisture that weeps in. So the key difference is that solid masonry forms a single load-bearing wall, while cavity masonry has an air space between wythes for insulation and moisture management.