Multi-residential buildings are increasingly popular on the Australian residential landscape with many Australians choosing to live in apartments and adopting inner-city lifestyles in the suburbs. However, the design and construction of multi-unit projects involve greater risks and regulations, creating new challenges for designers, contractors and workers. The use of the best-performing products can determine the success of each project, especially when meeting the fire and acoustic requirements of the Building Code of Australia (BCA).
Baines Masonry Blocks meets BCA’s fire resistance and acoustic performance requirements with their range of products and the newly designed Fire and Acoustic Calculator.
About fire resistance performance
The fire resistance performance of a masonry wall relies on three factors – structural adequacy, integrity and insulation. Each factor is expressed in terms of the number of minutes that the wall can resist a particular fire intensity defined by AS 1530.4-2005. For example a fire resistance level (FRL) of 180/120/120 implies 180 minutes of resistance for structural adequacy, 120 minutes of resistance for integrity and 120 minutes of resistance for insulation. Each characteristic is defined by AS 1530.4-2005 as follows:
1. Structural adequacy: The ability of a load-bearing element of construction to support a load when tested in accordance with AS 1530.4-2005.
2. Integrity: The ability of an element of construction to resist the passage of flames and hot gases from one space to another, when tested in accordance with AS 1530.4-2005.
3. Insulation: The ability of an element of construction to maintain a temperature on the surface that is not exposed to the furnace, below the limits specified, when tested in accordance with AS 1530.4-2005.
When a wall is in a non-load bearing situation, the FRL for structural adequacy is stated as a dash, e.g. -/120/120.
About acoustic performance
Where necessary, the acoustic performance of a wall must be considered in order to safeguard the occupants of a part of a building from illness or loss of comfort.
Key considerations for acoustic performance are airborne sound and impact generated sound.
Airborne sound is commonly measured by playing a series of differing frequency sounds on one side of a wall and measuring the sound loss on the other side. It is stated in terms of a weighted sound index (Rw); the higher the index value, the higher the element prevents the transmission of the sound. An adjustment factor is typically associated with the weighted sound index, which is called the spectrum adaption term (Ctr) and accounts for low frequency noise. This adjustment factor is always a negative number and is added to the weighted sound index to give a combined value lower than Rw. For example, an Rw of 53 with a Ctr of -6 gives an Rw + Ctr of 47. These values are typically obtained from testing in accordance with AS/NZS 1276.1 or ISO 717.
Baines blocks with fire and acoustic performance
Baines Masonry currently offers two types of concrete blocks that are recommended for builds requiring specific fire and acoustic performance. These are Betta Block units and Dense Weight units. Both types are available in various unit sizes and are suitable for core filled and non-core filled applications. Baines Masonry products are suitable for use in load bearing and non-load bearing walls for all types of buildings. The material composition and specific unit dimensions have been optimised, tested and assessed by leading organisations around Australia in order to provide exceptional fire and acoustic performance.
Baines Masonry has undertaken extensive non-load bearing fire testing of the Betta Block product range with CSIRO in North Sydney, NSW. The acoustic performance of internal Baines masonry walls has been assessed by a leading Australian acoustic firm. The results of each are outlined in the ‘Fire & Acoustic Technical Manual for Load Bearing & Non-Load Bearing Walls’.
Baines Masonry Fire and Acoustic Calculator
Based on their extensive knowledge and expertise in masonry, the team at Baines Masonry has devised a new Fire and Acoustic Calculator to take the hassle out of specification. This simple web-based tool has been specifically designed to address concerns surrounding compliance, fire protection and insulation. The Fire and Acoustic Calculator simplifies the selection of the correct product and BCA compliance, taking the guesswork out of specification, giving designers and specifiers the assurance that they are fully compliant with industry requirements, and significantly reducing their exposure to liability.
To use the tool, designers and specifiers are required to enter a few simple design parameters such as the required wall type, installation environment, acoustic and fire insulation requirements, and the relevant BCA requirement. The calculator instantly provides a tailored shortlist of Baines Masonry products that meet the specified parameters. The shortlist is also provided in printable PDF format, allowing the designer or specifier to retain a hard copy for reference or for insertion into tender documents.
