Many of us take the safety of our homes for granted and don’t worry about the possibility of roofs collapsing or floors giving in. This is thanks to the precise and exacting standards that the building industry operates under, including timber construction standards such as the ones published by Standards Australia.
By complying with these standards, builders, engineers, manufacturers and other professionals working in residential timber framed construction, satisfy the requirements of the Building Codes of Australia (BCA).
What are the standards for timber construction?
Australian standards for timber structures can be found in AS 1684, Residential timber-framed construction, also known as the Timber Framing Code. This code consists of four parts covering:
- Design criteria
- Building practices
- Bracing and span tables for timber framing members.
All of these parts are essential to building safe, stable homes that can resist the wind speeds and weather conditions of the location they are in. These criteria also form the reason behind why timber construction standards contain span tables specifying wind speeds.
The first part of the Timber Framing Code is for product manufacturers and designers, providing them with a standard reference to calculate timber sizes and forces to be resisted by tie-down and bracing. Parts two and three both cover requirements for building practice in non-cyclonic and cyclonic areas, respectively. Part four, which is not as commonly used as the former three parts, covers simplified design procedures, limited to wind classes N1 and N2; the two lowest non-cyclonic wind classes.
Scope of AS 1684.2
AS 1684.2 is the second part of the Timber Framing Code, focusing on non-cyclonic areas. It specifies the requirements for building practice and the selection, placement and fixing of various structural elements. This helps ensure builders construct sound dwellings, allowing consumers to trust that their homes are safe to inhabit. The Supplements to AS 1684.2 also provide span tables for a variety of timber stress grades in different wind conditions.
AS 1684.2 applies to timber-framed Class 1 and Class 10 buildings, as defined by the BCA. Class 1 buildings cover single-occupancy dwellings like a house or townhouse, guesthouses or hostels with fewer than twelve occupants, while Class 10 buildings include non-residential structures like a private garage or a swimming pool. The standard applies to the construction of these buildings, as well as any additions or alterations made to existing structures.
Why have standards for timber construction?
Timber frames are very widespread and popular in Australia, due to their comparatively low cost and because they are much more lightweight than steel frames. In fact, more than half of residential buildings in the country are timber framed constructions. This means it is extremely important to ensure that Australian standards address a wide range of timber construction practises and scenarios.
More generally speaking, construction standards result in better value and higher quality outcomes, both of which boost consumer confidence. For many Australians, purchasing a home is the ultimate dream come true. Knowing that the construction of their home was done to exacting standards like AS 1684.2 allows consumers to trust in the quality of the homes they buy and feel confident that structures will withstand outside forces.
Changes between the 2010 and 2021 editions
The Timber Framing Guide consistently updates and revises its standards to conform with changes in the industry and incorporate new research. To ensure comprehensive updates, it relies on highly trained technical committees such as Standards Australia’s Timber Committees, which consists of industry professionals who can provide the most up-to-date and accurate advice. The 2021 edition of AS 1684.2 is no different in its provision of necessary new standards. Important changes include:
● Flooring and decking changes to reflect current research, leading to more robust and quieter floors
● Clarifications around the definition of coupled roofs
● Addition of nail and screw fixings for thicker timber
● Bracing capacity change to reflect the use of common timber
● Change to details of metal tie-down connections
Additionally, the Timber Framing Guide was brought in line with accessibility requirements for online documents, allowing people with accessibility requirements to read the standards with ease.
Benefits of adopting AS 1684.2:2021 for timber construction
The construction industry is constantly evolving, with new technologies, materials and ideas developing and being brought in from other countries all the time. Between 2010 and 2021, Australia has seen a wider-scale adoption of a range of technologies and materials. New research into flooring and decking over the past decade has also had positive impacts on the quality of modern buildings. The revised Timber Framing Guide reflects these updates and, through corrections and revisions, provides the most accurate standard to date.
Stay on top of timber construction standards with AS 1684.2:2021
By integrating 1684.2:2021 into their practice, construction professionals not only comply with industry requirements, but can also improve on current practices and provide a better product for their clients. The revisions to AS 1684.2 have been carefully considered by a team of experts in the field, offering the most up-to-date guidance. To stay on top of timber constructions standards, purchase AS 1684.2:2021 here.