Discontinuous Construction
Discontinuous construction is a wall with two independent stud rows or masonry leaves, required by NCC 2022 for separating walls between dwellings.
Ask Chalkline about this →Discontinuous construction is a wall assembly where the two faces of the wall have no rigid solid connection between them. In framed walls this means two independent rows of studs with a clear gap, each carrying its own plasterboard layer, with nothing rigid (no noggings, no bridging timber, no pipes) crossing the gap from one row to the other. In masonry-plus-frame walls, the framing sits independently from the masonry leaf with no ties bridging across.
Breaking the rigid connection between the two faces stops airborne and impact sound from travelling directly through the wall structure. It reduces low-frequency flanking that defeats standard single-frame walls.
Under NCC 2022 Housing Provisions Part 10.7.1, discontinuous construction is mandatory wherever a separating wall divides a bathroom, sanitary compartment, laundry, or kitchen in one dwelling from a habitable room (not a kitchen) in the adjoining dwelling. The requirement applies to Class 1 buildings (duplexes, townhouses, terraces).
The most common on-site failure is a nogging, blocking piece, or pipe run that bridges the two stud rows, which re-creates the rigid connection and defeats the purpose of the double-stud assembly.
Also known as: discontinuous wall, double-stud wall (informal).
Category: Compliance & approvals.
Related
- NCC sound insulation, H4P6 and Part 10.7 requirements for separating walls