A cavity wall is a masonry wall built as two separate wythes, an outer brick or stone veneer and an inner structural wall, separated by a continuous air space that drains water and blocks it from reaching the interior.
The gap in a cavity wall does two jobs: it breaks the direct path for water that gets past the outer brick, and it interrupts moisture transfer between outside and in. Wall ties bridge the cavity to hold the wythes together without closing the gap. Flashing and weep holes sit at the base of the cavity and above any interruption like a window or lintel, catching water that gets through the veneer and routing it back outside before it ever touches the structural wall.
Most of the older homes we work on around Wytheville and Independence use some version of this system, even if it wasn't called that at the time. When mortar droppings fall into the cavity during original construction or a later repair, they bridge the gap and give water a path straight to the inner wall, which is a common hidden cause of interior dampness we find during a wall inspection.
More masonry vocabulary from the glossary.
The services where this term comes up.
Chelo's Brick & Stone serves Hillsville, Galax, Wytheville, Fancy Gap, and Independence, VA. Call for a straight answer and a free on-site estimate.
