NT Part 10.7 Sound insulation
NT 10.7.1 Sound insulation requirements2019: NT 22.214.171.124
- achieve the weighted sound reduction index (RW) and impact sound resistance required by Table NT 10.7.1; and
- be installed in accordance with the appropriate requirements of NT 10.7.2 and NT 10.7.3.
The wall configurations shown in Figures NT 10.7.1b, 10.7.1c, 10.7.1d, 10.7.1e, 10.7.1f, 10.7.1g, 10.7.1h, 10.7.1i, 10.7.1j, 10.7.1k, 10.7.1l, 10.7.1m, 10.7.1n, 10.7.1o, 10.7.1p, 10.7.1q, 10.7.1r, 10.7.1s and 10.7.1t are typical examples. Other proprietary methods are available for meeting the RW and sound impact levels required by NT 10.7.1.
|Separating wall — location and penetrations||Impact sound resistance (as per Figures NT 10.7.1b to 10.7.1h)||RW (as per Figures NT 10.7.1i to 10.7.1u)|
|Type A: between a bathroom, sanitary compartment, laundry or kitchen and a habitable room (other than a kitchen) in an adjoining Class 1 building (dwelling) (see Figure NT 10.7.1a)||Yes||50|
|Type B: in all other cases to those listed as Type A (see Figure NT 10.7.1a)||No||45|
|A soil and waste pipe or other penetration that serves or passes through a separating wall between houses — if the adjacent room is a habitable room (other than a kitchen)||No||45|
|A soil and waste pipe or other penetration that serves or passes through a separating wall — if the room is a kitchen or any other room||No||30|
NT 10.7.2 General installation requirements for walls2019: NT 126.96.36.199
- be installed in accordance with the appropriate requirements contained in (2) to (6); and
- at the junction of sound insulated walls with perimeter walls and roof cladding, be sealed in accordance with any details in Figure NT 10.7.2a.
- be laid with all joints filled solid, including those between the masonry and any adjoining construction; and
- not be chased for services.
- If one layer is required under this Part, joints must be staggered with the joints in sheets on the opposite face of the wall.
- If 2 layers are required, the first layer must be fixed according to (a) and the second layer must be fixed to the first layer with nails, screws or adhesive so that the joints do not coincide with those of the first layer (see Figure NT 10.7.2b).
- Joints between sheets or between sheets and any adjoining construction must be taped and filled solid.
- Fire-protective grade plasterboard (where nominated) must be the grade manufactured for use in fire-resisting construction.
- The section of steel must be not less than 0.6 mm thick.
- Studs must be not less than 63 mm in depth unless another depth is specified in NT 10.7.1.
- Studs must be fixed to steel top and bottom plates of sufficient depth to permit secure fixing of the plasterboard.
- All steel members at the perimeter of the wall must be securely fixed to the adjoining structure and be bedded in resilient compound or the joints must be caulked so that there are no voids between the steel members and the wall.
- Studs must be fixed to top and bottom plates of sufficient depth to permit secure fixing of the plasterboard.
- Noggings and like members must not bridge between studs supporting different wall leaves.
- All timber members at the perimeter of the wall must be securely fixed to the adjoining structure and bedded in resilient compound or the joints must be caulked so that there are no voids between the timber members and the wall.
NT 10.7.3 Soil and waste pipes2019: NT 188.8.131.52
If a soil or waste pipe passes through a separating wall—
- a door or panel providing access to the pipe must not open into any habitable room, other than a kitchen; and
- an access door or panel in any other part must be firmly fixed so as to overlap the frame or rebate of the frame by not less than 10 mm, be fitted with a sealing gasket along all edges and constructed of—
- wood, plasterboard or blockboard not less than 38 mm thick; or
- compressed fibre reinforced cement sheeting not less than 9 mm thick; or
- other suitable material with a mass per unit area not less than 24.4. kg/m2.