38
Thickness
of external
and party walls.
12
together with good cement or lime mortar to the satisfaction of the Building Authority. Except where specially permitted in this Ordinance, no part of such wall shall be thicker than any part underneath it, and all cross walls and return walls shall be properly bonded into main walls. Sound blue bricks may be used in the walls of the uppermost storey only of a building, or, where such storey exceeds fifteen feet in height, in the uppermost fifteen feet of the walls of such storey; but blue bricks may not, without the approval of the Building Authority, be used in the walls of the other storey or storeys.
17.—(1) Every person who erects a new building shall construct every external and every party wall of such building not exceeding thirty-five feet in length, clear of cross walls, in accordance with the following rules, and in every case the thickness prescribed shall be the minimum thickness of which such wall may be constructed :-
(a) Where the wall does not exceed 12 feet in height, it shall be 9 inches thick for its whole height.
(b) Where the wall exceeds 12 feet but does not exceed 25 feet in height, it shall be 13 inches thick for its whole height.
(c) Where the wall exceeds 25 feet but does not exceed 40 feet in height, the wall in the lowermost storey, and in any space underneath such storey, shall be 18 inches thick, and in the other storey or storeys 134 inches thick.
(d) Where the wall exceeds 40 feet but does not exceed 55 feet in height, the wall in the lowermost storey, and in any space underneath such storey, shall be 22 inches thick, the wall in the next storey 18 inches thick, and in the other storey or storeys 131⁄2 inches thick.
(e) Where the wall exceeds 55 feet but does not exceed 70 feet in height, the wall in the lowermost storey, and in any space underneath such storey, shall be 27 inches thick, the wall in the next storey 22 inches thick, the wall in the next storey 18 inches thick, and in the other storey or storeys 13 inches thick.
(f) Where the wall exceeds 70 feet but does not exceed SO feet in height, the wall in the lowermost storey, and in any space underneath such storey, shall be 311⁄2 inches thick, the wall in the next storey 27 inches thick, the wall in the next storey 22 inches thick, the wall in the next storey 18 inches thick, and in the other storey or storeys 13 inches thick.
Provided that-
(i) in cases where the number of storeys is less than that indicated in the foregoing rules or where the walls are con- structed in good cement mortar, the respective thicknesses of the walls shall be determined by the Building Authority;
(i) in the case of two-storied buildings and of the upper- most two storeys of buildings containing a greater number of storeys, the walls may be 13 inches thick throughout the height of such two storeys, provided such height does not exceed 25 feet;
(i) no storey shall exceed in height 16 feet without the permission of the Building Authority, who shall in such case prescribe to what extent, if any, the walls shall be increased in thickness. Such increase of thickness may be provided for by piers of the required thickness and of such collective length, not exceeding one.fourth part of the length of the walls, the Building Authority may require.
as
1