Remedial Building Australia
Technical Remedial Building Platform
← Back to Miscellaneous & Other

Miscellaneous & Other

Acoustic Issues

Acoustic performance deficiencies in Class 2 buildings — insufficient sound insulation between lots, inadequate impact sound control, and excessive external noise transmission — are a frequent source of resident complaints and strata disputes. The National Construction Code (NCC) requires that separating floors and walls between habitable rooms in different dwellings achieve minimum Weighted Sound Reduction Index (Rw) and Weighted Standardised Impact Sound Pressure Level (LnTw) values. Deficiencies from construction shortcuts, incorrect materials or poor detailing can result in acoustic performance substantially below the NCC requirements, with remediation often requiring invasive construction works.

Common Signs

  • Airborne noise from adjacent apartments clearly audible — conversation, television, music
  • Impact noise — footsteps, dropped objects — transmitted from the floor above
  • External traffic or aircraft noise significantly louder than expected
  • Noise from building services (pumps, lifts, air conditioning) audible in habitable rooms
  • Complaints escalating between adjacent lot owners from recurring noise
  • Acoustic consultant measurements confirming sub-NCC performance
  • Noise flanking around separating walls through continuous ceiling or floor elements

Common Causes

  • Lightweight separating floor construction without adequate mass or resilient layer
  • Floating floor systems with isolated resilient mounts incorrectly installed — acoustic bridging
  • Penetrations through separating walls and floors not acoustically sealed
  • Flanking noise paths through continuous concrete elements bypassing the separating assembly
  • External glazing with insufficient sound reduction for the external noise environment
  • Building services not isolated from the structure — vibration transmitted to habitable rooms
  • Construction shortcuts — missing acoustic batts, direct-fixed floor finishes over concrete

Risk of Neglect

  • Ongoing resident amenity loss from inadequate sound insulation
  • Strata disputes and NCAT applications from affected lot owners
  • Legal liability for building defects not meeting NCC acoustic requirements
  • Invasive and expensive remediation required — often requiring floor or ceiling strip-out
  • Impact on property values and marketability of affected lots
  • Building Commission and warranty claims against builders
  • Difficulty in achieving acoustic compliance on retrofit works within existing construction

Inspection Requirements

Download Inspection Checklist
  • Engage a NATA-accredited acoustic consultant to conduct sound transmission measurements between representative adjacent lots.
  • Test both airborne sound (Rw) and impact sound (LnTw) between all separating floor and wall combinations.
  • Compare measured performance against NCC Volume 1 F5.5 requirements for the building class.
  • Identify all flanking paths — measure noise levels in rooms not directly adjacent to the sound source to identify flanking routes.
  • Inspect separating floor construction to confirm the specification of resilient layers, mass and decoupling.
  • Inspect acoustic sealing at all penetrations through separating walls and floors — services, skirtings, cornices.
  • Assess glazing acoustic performance in external-noise-exposed rooms.
  • Engage the acoustic consultant to prepare the remediation specification based on measurement findings.
Start Inspection Checklist

Create a project inspection record, add defect locations, upload photos, and save notes for scope writing.

Typical Repair Methodology

  1. 01.Engage an acoustic consultant to confirm the acoustic upgrade specification before any works commence.
  2. 02.For inadequate separating floors — install a floating floor system using resilient mounts or resilient underlay over the full floor area.
  3. 03.Ensure no acoustic bridges exist between the floating floor and the structural slab — check all fixings, skirting boards and services penetrations.
  4. 04.For inadequate separating walls — install additional plasterboard layers with resilient battens or staggered stud systems.
  5. 05.Seal all penetrations through separating walls and floors with acoustic-grade mineral wool and fire-rated acoustic sealant.
  6. 06.Install acoustic boxing around all building services penetrating through separating elements.
  7. 07.For external noise — upgrade glazing to acoustically rated double or laminated glass.
  8. 08.Conduct post-upgrade acoustic testing to confirm NCC compliance.
  9. 09.Record all acoustic test reports, product specifications and installation photographs.

Related Repair Systems

  • Floating floor acoustic systems
  • Resilient ceiling systems
  • Acoustic wall lining systems
  • Penetration acoustic sealing systems
  • Acoustic glazing upgrade systems
Open Repair Systems →