Is it acceptable for lifting holes in the sub-deck of cassette floors for timber or steel frame construction to be left untreated?
The required acoustic performance of any of the robust detail timber or steel frame separating floors would not be affected if lifting holes within the sub-deck remain untreated, provided: • each lifting hole is no larger than 120mm in diameter • mineral wool quilt, of the appropriate specification as indicated in the relevant separating floor specification, is provided covering the whole area of the floor, between the joists/battens, in both the structural floor void and the floating floor void • all other relevant requirements are strictly followed.Lifting holes that are larger than 120mm in diameter should be sealed or covered with a board or panel of similar or greater density than the sub-deck board.
