How can I ensure my wall junctions perform well?

What makes a good wall junction design?

One of the most important things to consider from an acoustic standpoint in the design of wall junctions is the reduction of flanking transmissions. The following points represent some general tips, as well as some specific advice for certain types of wall junction.

General Advice

  • Direct contact between the wall lining and floor finish board should be avoided, to reduce vibration transfer. Wall plasterboard linings should be stopped about 5 mm above the floor decking. The gap should be filled with acoustic sealant for light steel separating floors.
  • Where a separating floor meets an external or parti wall, the void within the wall between the studs should be filled with mineral wool to at least 300 mm above and below the separating floor.
  • A light steel frame inner leaf structure of an external wall should not be continuous across a junction with a separating wall. A physical break should be maintained, and any sheathing board should also be discontinuous at this.
  • Where a separating wall meets an internal wall or external wall, additional mineral wool should be placed between the wall studs adjacent to the junction of the inner leaf of the external wall. However, in many cases, the inner leaf of the external wall will be filled with mineral wool for thermal insulation.
  • Internal non-load bearing walls within an apartment should, if possible, not break through the ceiling of a separating floor, and should not touch the steel floor joists.
  • Air paths through separating elements should be avoided.
  • Joints in successive layers of lining board should be staggered.
  • Any gaps should be sealed with acoustic sealant.

Specific Advice

Separating walls with separating floor

Light steel separating floor

Composite separating floor

Separating wall with internal floor

Junctions between two separating walls

Separating wall with external wall

Separating wall with internal wall

Separating floor with external wall

Light steel separating floor

Composite separating floor

Separating floor with internal wall

Load bearing internal wall

Non load bearing wall