Stair treatment 1 - stair covering and independent ceiling with absorbent material

Stair treatment 1 – stair covering and independent ceiling with absorbent material (see Diagram 4.8). Lay soft covering of at least 6 mm thickness over the stair treads. Ensure it is securely fixed (e.g. glued) so it does not become a safety hazard. If there is a cupboard under all, or part, of the stair – (a) line the underside of the stair within the cupboard with plasterboard of minimum mass per unit area 10 kg/m2 and an absorbent layer of mineral wool (minimum density 10 kg/m3), within the space above the lining; and (b) build cupboard walls from two layers of plasterboard (or equivalent) with staggered joints, each sheet of minimum mass per unit area 10 kg/m2; and (c) use a small, heavy, well fitted door for the cupboard. Where there is no cupboard under the stair, construct an independent ceiling below the stair (see para 4.26 Floor treatment 1).