i) every wall shall be constructed of brick, stone, concrete or other durable material and shall have a smooth internal surface without cracks or open joints.
i) udonga ngalunye luyakwakhiwa ngezitena, amatye, ikonkriti okanye ezinye izinto eziluqilima kwaye ziya kuba nodonga lwangaphakathi olugudileyo olungenazintanda okanye ijoyini ezivulekileyo.