hollow brick

hollow brick

1. (US) A hollow clay masonry unit whose net cross-sectional area in every plane parallel to the bearing surface is not less than 60% of its gross cross-sectional area measured in the same plane. 2. (Brit.) A brick having holes through it which total at least 25% of its volume, the holes being not less than 3/4 in. (1.91 cm) wide or 3/4 sq in. (4.84 sq cm) in area.