Type 3. Airborne resistance varies depending on floor construction,
absorbency of materials, extent of pugging and partly on
the floating layer. Impact resistance depends mainly on the
resilient layer separating floating from structure.Note: Minimum mass per unit area = 25 kg/m^2
Floating layer: 18 mm timber or wood based board, t & g joints
glued and spot bonded to a sub-strate of 19 mm plasterboard.Alternatively, cement bonded particle board in 2 thicknesses †
24 mm total, joints staggered, glued and screwed together.
Resilient layer: 25 mm mineral fibre, density 60†100 kg/m^3.
Base: 12 mm timber boarding or wood based board nailed to joists.
Absorbent material: 100 mm unfaced rock fibre, minimum density
10 kg/m^3.
Ceiling: 30 mm plasterboard in 2 layers, joints staggered.Sound Insulation---Floors