Separating floors - Stair treatment 

Stairs are subject to the same sound insulation requirements as floors where they form a separating function.

. Follow detail provided by diagrams 4-1 and 4-8 of Approved Document E,

. Where there is no cupboard under the stairs: An independent ceiling should be constructed below and use Rockwool Flexi slab within the construction,

. Where there is a cupboard under the stairs: Lay soft covering min 6 mm thick over treads. Line underside of stairs with min 1 layer of plasterboard (mass 10 Kg/m2). Fill space above lining with Rockwool Flexi. Build cupboard walls using 2 layers of wallboard (each having min mass 10 Kg/m2).
Use small, heavy and well fitted cupboard door,

. Pre-completion site testing is required.