(1) Impregnation and moisture content.- Cut wooden shingles shall be impregnated in accordance with the requirements in accordance with the requirements of S.A.B.S. 448, South African wood shingles for roofs and walls, and shall also conform to the moisture-content clause of that specification.

(2) General requirements.- Cut wooden shingles shall comply with the following requirements-

a. shingles shall taper from butt to tip and shall be made to the following requirements-

(i) the nominal lengths of shingles shall be not less than 400 millimetres;

(ii) the widths of shingles shall be any random width from 100 millimetres to 200 millimetres;

b) the maximum permissible butt exposure shall vary with the roof slope, in accordance with Table VI;

c) values of maximum permissible butt exposure for roof-slopes between 26 and 34 degrees, and for shingles of different length from that specified in paragraph (a), shall be obtained by linear interpolation;

d) in no case shall the roof-slope be less than 20 degrees.

TABLE VI