Floor treatment 2 – platform floor with absorbent material: Construction specification

Where this treatment is used to improve an existing timber floor, a layer of mineral wool (minimum thickness 100 mm, minimum density 10 kg/m3) should be laid between the joists in the floor cavity. The floating layer should be – a minimum of two layers of board material; minimum total mass per unit area 25 kg/m2; each layer of minimum thickness 8 mm; and fixed together (e.g. spot bonded or glued/screwed) with joints staggered. The floating layer should be laid loose on a resilient layer. The resilient layer specification is – mineral wool, minimum thickness 25 mm, density 60 to 100 kg/m3; and the mineral wool may be paper faced on the underside. Note – The lower figure of density for the resilient layer gives the best insulation but a "softer" floor. In such cases additional support can be provided around the perimeter of the floor by using a timber batten with a foam strip along the top attached to the wall.