(1) Solid bearing-walls less than 215 millimeters in thickness, and cavity bearing-walls having both leaves not thicker than 100 millimeters each, shall not be broken into, subsequent to being built, for the insertion of beams or rafters, except with the written approval of the local authority.

(2) Timber beams and joists supported upon masonry shall have a bearing at least 75 millimeters in length at each point of support.

(3) beans and girders, other than loose of timber, in empirically constructed buildings shall have an area of bearing masonry in accordance with the provisions of section 41.

(4) In buildings not empirically constructed, the bearings shall be such as yo prevent stresses in the masonry exceeding those specified in sections 63 to 73 or in section 78.