FAQs - Acoustic
Does DCS achieve simultaneous impact and airborne sound compliance?
Why is DCS acoustically better than conventional discontinuous party walls consisting of stud walls?
- The quality of pipe fixing to avoid water hammering is not reliant on the workmanship of the installer.
- The system provides better insulation for heat loss in hot water pipes. This ensures significant energy saved for water heating and eliminates water wastage due to availability of hot water in a shorter time.
- Additional water pipes or power/communication cables can be installed even after the construction of an existing building utilising DCS. The overall wall thickness is significantly reduced.
- Water hammer is significantly reduced or eliminated on both sides of the party wall.
- Unlike copper pipes, cross linked polyethylene pipes do not need maintenance since there is no build-up of water impurities in the pipes. This eliminates the need to install water in accessible spaces like stud walls.
- It is a cheaper and faster way to build in comparison to other alternatives.
Does 150mm concrete party walls with daub glue fixed plasterboard finishing comply with the building code of Australia (BCA)?
No. 150mm concrete walls (without electrical/water conduits or joints) provide Rw + Ctr = 47 dB. However, the Building Code of Australia accepts the above as a “deemed to satisfy” condition even though the minimum BCA requirement to comply is Rw + Ctr = 50 dB.
A 150mm concrete party wall with plasterboard cladding can no longer be treated under the “deemed to satisfy” conditions. Plasterboard attached to concrete faces with daub glue results in resonance in the plasterboard (i.e. drum effect) causing significant transmission loss. This eliminates the possibility of a 150mm concrete wall complying with the BCA.
BCA, Specification 5.2, Table 2 shows a 150mm concrete wall with plasterboard on 28mm furring channels which DOES NOT COMPLY. Daub glue provides up to 2mm to 4mm gaps between the wall and plasterboard surfaces in lieu of the 28mm gap of furring channels. Resonance of plasterboards increases when the gap between the wall and plasterboard gets smaller hence increases transmission loss. As a result, a 150mm concrete wall with daub glued plasterboard DOES NOT COMPLY WITH THE BCA.