Evolution of Masonry Cavity Wall Designs.

Cavity walls became the norm when architects and masons came to the realization a simple empty space separating two wythes of masonry with a layer of insulation on the cavity side of the concrete masonry unit (CMU) could provide as much comfort as several feet of solid masonry. This article compares three multiwythe masonry cavity wall designs--from the simple multi-wythe masonry cavity wall to the more sophisticated pressure-equalized cavity wall. All of them have an exterior brick veneer wythe (acting as a rainscreen and providing a drainage plane on the back of the brick), a supporting wythe of 200-mm (8-in.) CMU, and a separating cavity partly filled with insulation. Geographically, the discussion is limited to commercial construction in the northern United States and Canada, where the winters are cold and summers are warm to hot. [ABSTRACT FROM AUTHOR]