Describes requirements for cold formed aluminium and steel planks for use in flooring, walkways and stair treads. Gives definitions, materials, sizes, permissible deviations, performance, marking, method of test for strength and deflection, information to be given to the manufacturer or supplier in an enquiry or order and recommendations for installation of planks. Illustrates types of plank, imposed load on treads, staggered layout of planks, securing planks to supporting members and in-line layout of planks.