SEPARATING WALLS (NEW BUILDINGS) SOUNDPROOFING

2.70 Wall type 2.2 Two leaves of lightweight aggregate block with 75 mm cavity, plaster on both room faces (see Diagram 2-16)

• minimum mass per unit area including plaster 300 kg /m2
• minimum cavity width of 75 mm
• 13 mm plaster on both room faces

Example of wall type 2.2

The required mass per unit area would be achieved by using:

• 100 mm block leaves
• block density 1375 kg /m3
• 225 mm coursing
• 13 mm lightweight plaster (minimum mass per unit area 10 kg /m2) on both room faces

This is an example only. See Annex A for a simplified method of calculating mass per unit area. Alternatively use manufacturer’s actual figures where these are available.

Diagram 2-16: Wall type 2.2

Additional construction: Wall type 2.3 should only be used where there is a step and/or stagger of at least 300 mm.

2.71 Wall type 2.3 Two leaves of lightweight aggregate block with 75 mm cavity and step/stagger, plasterboard on both room faces (see Diagram 2-17)

• minimum mass per unit area including plasterboard 290 kg /m2
• lightweight aggregate blocks should have a density in the range 1350 to 1600 kg/m3
• minimum cavity width of 75 mm
• plasterboard, each sheet of minimum mass per unit area 10 kg /m2, on both room faces

Note: The composition of the lightweight aggregate blocks contributes to the performance of this construction with a plasterboard finish. Using denser blocks may not give an equivalent performance.

Example of wall type 2.3

The required mass per unit area would be achieved by using

• 100 mm block leaves
• block density 1375 kg /m3
• 225 mm coursing
• plasterboard, each sheet of minimum mass per unit area 10 kg/m2,on both room faces

This is an example only. See Annex A for a simplified method of calculating mass per unit area. Alternatively use manufacturer’s actual figures where these are available.

Note: Increasing the size of the step or stagger in the separating wall tends to increase the airborne sound insulation

Diagram 2-17: Wall type 2.3

Resistance to the passage of sound 25