(1) Marseilles-pattern and plain-clay roofing tiles shall comply with the requirements of S.A.B.S. 623, Clay roofing tiles.

(2) Clay roofing tiles, other than Marseilles-pattern and plain tiles, shall be made accurate to their nominal dimensions with the following tolerances-

a. thickness: 2 millimetres(for plain tiles tiles only);
b. breadth: ±3 per centum of nominal breadth;
c. length: ± 3 per centum of nominal length.

(3) Detailed requirements.- The detailed requirements for clay roofing tiles shall be in accordance with the provisions of subsection (2) of section 20.