Hierarchy classification:

1. top of the aat hierarchies
2. Materials Facet
3. Materials (hierarchy name)
4. materials (substances)
5. [materials by composition]
6. inorganic material
7. clay
8. [clay by product]
9. brick (clay material)
10. [brick by form]
11. [brick by form: solidity]

Anotations

Scope note:

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. In British usage it refers to a brick with holes in it that 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.