Any Australian architect, designer or builder is all too aware that selecting the right product for the right project can be frustrating and time consuming. Ensuring adherence to the BCA with the varying requirements across different project types can require in-depth research and cross referencing.

For ceiling & walls, achieving the necessary requirements for fire resistance and acoustic performance is critical to meeting BCA Deemed to Satisfy provisions. Knowing the exact requirements is essential for avoiding non-compliancy.

Fire Resistance

The fire resistance required of a building will be dictated by the type of construction. Multi-residential developments which are at higher risk with more storeys and higher occupancy will require higher fire resistance than stand-alone residences.

Once the type of construction is determined, the Fire Resistance Level (FRL) is then specified.

Fire Resistance Level of wall and ceiling products, as defined in the Building Code of Australia (BCA) is the grading period, in minutes, for three performance criteria:

  • Structural adequacy – Failure occurs when the specimen collapses under load
  • Integrity – Failure occurs when the specimen develops cracks or openings through which flames or hot gases can pass
  • Insulation – Failure occurs when the temperature of the unexposed surface of the specimen reaches a certain level

Therefore an FRL requirement for a wall of 90/60/30 would mean that the wall must maintain structural adequacy for 90 minutes, integrity for 60 minutes and insulation for 30 minutes.

Acoustic performance

BCA requirements for acoustic performance will also vary greatly from project to project. Of particular focus is the acoustic performance in multi-residential projects, where reducing noise travelling between apartments is critical to the acoustic comfort of residents.

Acoustic performance is measured on:

Rw – ‘Weighted sound reduction Index’.  Rw is measured in decibels. 1Rw equates to approximately 1db noise reduction; therefore 40Rw would be a weighted sound reduction of 40db. It is an indication of the sound reduction of a wall or floor system at mid-frequencies such as speech. The higher the Rw the greater sound reduction. The minimum BCA requirement for separating a sole occupancy unit and corridor is Rw 50.

Rw+Ctr – ‘Weighted sound reduction index with spectrum adaptation term’. Is used to account for low frequency noise such as home cinema, traffic etc. The higher the Rw+Ctr the greater the ability of the wall to control low frequency noise. The minimum BCA requirement for separating sole occupancy units is Rw+Ctr 50. Thus a greater sound reduction needed between residences.

Ln,W+Ci – ‘Weighted Normalised Impact Sound pressure Level with Spectrum Adaptation Term’ Is the ability of the floor/ceiling system to isolate impact noise such as foot falls. Unlike Rw and Rw+Ctr the lower rating the better it isolates sound.

Specifying made simple

To address the needs of Australian specifiers, USG Boral has created Systems+, a “one-stop shop” for specifying fire and acoustic rated wall and ceiling solutions to BCA requirements.

Systems+ is an innovative and cost-effective solution for specifying in any development, and addresses the unique requirements of different projects, including multi-res, commercial, educational or health care.

Systems+ allows specifiers to select and compare the entire range of USG Boral including Multiframe™, Partiwall® & IntRwall™ products, providing colour coded and clearly marked page headers with prominently displayed system names and ratings for quick and simple specification that help guarantee compliance.