NCC 2016 Volume One
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Specification F5.2 Sound Insulation for Building Elements
This Specification lists the weighted sound reduction index Rw for some common forms of construction.
Wall systems listed in Table 2 having a minimum 20 mm cavity between 2 separate leaves, with—
for masonry, where wall ties are required to connect leaves, the ties are of the resilient type; and
for other than masonry, there is no mechanical linkage between leaves except at the periphery,
are deemed to be discontinuous construction.
The forms of construction listed in Table 2 for wall construction and Table 3 for floor construction, are considered to have the Rw, Rw + Ctr and Ln,w stated in that Table. The forms of construction must be installed as follows:
Masonry — Units must be laid with all joints filled solid, including those between the masonry and any adjoining construction.
Concrete slabs — Joints between concrete slabs or panels and any adjoining construction must be filled solid.
Sheeting materials—
if one layer is required on both sides of a wall, it must be fastened to the studs with joints staggered on opposite sides; and
if two layers are required, the second layer must be fastened over the first layer so that the joints do not coincide with those of the first layer; and
joints between sheets or between sheets and any adjoining construction must be taped and filled solid.
Timber or steel-framed construction — perimeter framing members 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 framing members and the adjoining structure.
Services—
Services must not be chased into concrete or masonry elements.
A door or panel required to have a certain Rw + Ctr that provides access to a duct, pipe or other service must—
not open into any habitable room (other than a kitchen); and
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 be constructed of—
wood, particleboard or blockboard not less than 33 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.
A water supply pipe must—
only be installed in the cavity of discontinuous construction; and
in the case of a pipe that serves only one sole-occupancy unit, not be fixed to the wall leaf on the side adjoining any other sole-occupancy unit and have a clearance not less than 10 mm to the other wall leaf.
Electrical outlets must be offset from each other—
in masonry walling, not less than 100 mm; and
in timber or steel framed walling, not less than 300 mm.
Table 2 ACCEPTABLE FORMS OF CONSTRUCTION FOR WALLS
Description | Rw+Ctr (not less than) | Rw (not less than) | Construction |
---|---|---|---|
Wall construction type: Masonry | |||
Two leaves of 110 mm clay brick masonry with—
|
50 | 50 |
|
Two leaves of 110 mm clay brick masonry with—
|
50 | 50 |
|
Single leaf of 110 mm clay brick masonry with—
|
50 | 50 |
|
Single leaf of 90 mm clay brick masonry with—
|
50 | 50 |
|
Single leaf of 150 mm brick masonry with 13 mm cement render on each face. | - | 50 |
|
Single leaf of 220 mm brick masonry with 13 mm cement render on each face. | 50 | 50 |
|
110 mm thick brick masonry with 13 mm cement render on each face. | - | 45 |
|
110 mm thick concrete brickwork. | - | 45 |
|
Wall construction type: Concrete | |||
150 mm thick concrete panel. | 50 | 50 |
|
150 mm thick concrete panel with one layer of 10 mm plasterboard fixed to 28 mm metal furring channels on each face. | - | 50 |
|
200 mm thick concrete panel with one layer of 13 mm plasterboard or 13 mm cement render on each face. | 50 | 50 |
|
100 mm thick concrete panel with—
|
50 | 50 |
|
125 mm thick concrete panel with—
|
50 | 50 |
|
125 mm thick concrete panel. | - | 50 |
|
100 mm concrete panel with 13 mm cement render or one layer of 13 mm plasterboard on each face. | - | 50 |
|
190 mm thick concrete blockwork. | - | 45 |
|
140 mm thick concrete blockwork, the face shell thickness of the blocks being not less than 44 mm and with—
|
- | 45 |
|
Concrete panel - 100 mm thick. | - | 45 |
|
Note: For the purposes of this table the term "concrete panel" is a reference to a solid in-situ concrete panel or solid precast concrete panel. | |||
Wall construction type: Autoclaved aerated concrete | |||
75 mm thick autoclaved aerated concrete wall panel with—
|
50 | 50 |
|
75 mm thick autoclaved aerated concrete wall panel with—
|
50 | 50 |
|
Two leaves of 75 mm autoclaved aerated concrete wall panel with—
|
50 | 50 |
|
75 mm thick autoclaved aerated concrete wall panel with—
|
- | 50 |
|
Wall construction type: Timber and steel framing | |||
Two rows of 90×35 mm timber studs or two rows of 64 mm steels studs at 600 mm centres with—
|
50 | 50 |
|
Two rows of 64 mm steel studs at 600 mm centres with—
|
50 | 50 |
|
One row of 92 mm steel studs at 600 mm centres with—
|
- | 50 |
|
One row of 64 mm steel studs with 2 layers of 16 mm fire-protective grade plasterboard fixed to each face. | - | 45 |
|
One row of 64 mm steel studs with—
|
- | 45 |
|
One row of 64 mm steel studs with two layers of 13 mm plasterboard on each face. | - | 45 |
|
Table 3 ACCEPTABLE FORMS OF CONSTRUCTION FOR FLOORS
Description | Rw+Ctr (not less than) | Ln,w (not more than) | Rw (not less than) | Construction |
---|---|---|---|---|
Floor construction type: Concrete | ||||
150 mm thick concrete slab with—
|
50 | 62 | 50 |
|
200 mm thick concrete slab with carpet on underlay. |
50 | 62 | 50 |
|
100 mm thick concrete slab. |
45 | - | 45 |
|
Floor construction type: Autoclaved aerated concrete | ||||
75 mm thick autoclaved aerated concrete floor panel with—
|
50 | 62 | 50 |
|
Floor construction type: Timber | ||||
19 mm thick chipboard floor sheeting with—
|
50 | 62 | 50 |
|
19 mm thick tongued and grooved boards with—
|
45 | - | 45 |
|