(1) Floors.-Basement-floors shall be-
a) damp-proof; and
b) where ground-water is present or is likely to rise above such floor -level and is to be drained away from the building, the floor shall be laid on a layer, of not less than 100 millimetres in thickness, of broken stone, rubble or other fragmented material, the underside of which layer shall be above the top of the footing of any wall or column.
(2) Walls.- Basements-walls shall be provided with vertical damp-proof courses where damp-proof courses are required by section 2, and shall be in accordance with the provisions of section (4) of section 3.
(3) Where ground-water is present or is likely to rise above basement-floor level and is to be drained away from the building, a layer of fragmented material of not less than 75 millimetres in horizontal thickness shall be placed between the walls and any back-filing. Such layer shall-
a) communicate with the layer of similar material under the floor; and
b) extend to a level of 150 millimetres above the highest level of the water-table.
(4) Junction of floor and wall.-The junction between basement-floors and walls and columns shall be rendered damp-proof, unless, in the case of internal walls and columns, the floor itself has been rendered damp-proof or waterproof.
(5) Disposal of ground-water.-Where ground-water is present or is likely to rise above the basement-floor level and such water is to be prevented from entering the building-
a) means shall be provided by gravity or by pumping effectively to drain the water from the fragmented material around the walls and from under the floor of the basement; or
b) the basement shall be made waterproof to a level of at least 150 millimetres above the highest level of the water-table at the site.
(6) Where water is to be allowed to enter any building, weep-holes shall be made in the lowest floor or in the walls as such floor-level, and the water led by channels to a sump from where it shall be pumped away to a discharge-point indicated by the local authority.