Build with timber in a BAL-rated location? Yes, you can

WITH bushfire season approaching, thoughts turn to designing and building to minimise the potential risk of damage to homes in areas that may be affected.

While some people imagine that doing so would preclude the use of wood and wood products, it is not the case.

You can use timber framing and wood products in other applications for residential construction in BAL (Bushfire Attack Level) rated locations, subject to the requirements of Australian Standard AS3959 Construction of buildings in bushfire-prone areas.

Developed and refined over many years, the Australian Standard AS3959 Construction of buildings is bushfire-prone areas reflects the latest in building and materials science, technology and systems. The standard is a consensus-based document that is referenced by the National Construction Code.

Designing to ‘build out’ the effects of bushfires seeks to minimise the risk of ember, radiant heat and even flame damage. With appropriate design decisions that meet the requirements of AS 3959, attractive timber homes can be built, using sustainably sourced wood and wood products both inside and out.

Bushfire Attack Levels (BAL) are calculated to assess the degree of risk of bushfire attack of an individual building site. There are six BAL ratings and each has specific construction requirements relating to the materials that may be used, and how they are used, in residential construction.

Timber can be used for house framing and all interior applications, including flooring, skirting, architraves and cabinetry in all BALs.

“Understanding what is required for each BAL is actually quite straightforward,” said Boris Iskra, a structural engineer with additional fire qualifications, who is the National Codes and Standards Manager at Forest and Wood Products Australia Ltd (FWPA).

A key requirement of the Standard is to limit the size of gaps to reduce the potential entry of burning embers, as well as to protect the occupants and building from the effects of radiant heat from a bushfire.

Through the Wood. Naturally Better™ (naturallybetter.com.au) and WoodSolutions (woodsolutions.com.au) websites, FWPA provides a range of resources to help owners, designers and builders enjoy the aesthetic, functional and environmental benefits of wood in BAL locations, while meeting the requirements of the Australian Standard.

These free resources include a comprehensive design guide, Building with Timber in Bushfire-prone Areas, a calculator that allows people to estimate the BAL of their site and an expert advice service through which people can seek answers to their bushfire design-related questions.

“I encourage people to go to the websites and look at the resources,” Mr Iskra said.

“It would be a great pity if people missed out on gaining all the advantages of wood just because they didn’t have the information about how to use it in ways that comply with the Standard.”