(1) Materials.- Concrete roofing tiles shall comply with requirements of C.A.S. 187, Concrete roofing tiles.

(2) Details requirements.- The following requirements shall be met in regard to the laying and securing of concrete roofing tiles on the roof-

a) except as provided for in paragraph (b), the roof-slope shall be not less than-

Side-lap End-lap Minimum slope
25 mm 75mm 26½ degrees
38mm 108 mm 17½ degrees

b) where additional weatherproofing, such as the use of an under-felt or a sheet-metal layer or other method approved by the local authority, is provided, the roof-slope may be less than 17½ degrees, and in that case shall be not less than 15 degrees. If an under-felt is used on boarding, the battens shall be mounted on counter-battens, to ensure drainage.