definition
strict definition
clay
A continuous floor of fine-grained earthen minerals, either baked as a surface or naturally present beneath a structure.
A clay floor is composed of fine-grained earthen minerals, either baked to form a continuous surface, or occurring naturally on the site covered by the structure. This type does not include clay tiles, which are listed as ceramic tiles.
The floor can use earthen material already present on the site. It need not consist of separately manufactured units.
Ceramic tiles remain excluded even though they are made from clay. The continuous earthen surface distinguishes this entry from a floor assembled from those tiles.
