Building in Bushfire Zones with Ligna Stone

Timbercrete Fire Torch

Bushfires can ignite and spread quickly, making evacuation impossible. As a result, buildings need to be able to survive the full force of a bushfire and provide refuge to the occupants. In Australia we are highly prone to bushfires and hence need building materials with better fire resistant capacities.

Here is a brief overview of what makes building in bushfire zones more complicated and why Ligna Group’s Ligna Stone products offer an award winning solution for a highly fire-resistant building material.

The Requirements of Building Materials for Bushfire Zones

Building in areas that are prone to bushfires comes with many additional design, engineering and construction criteria that cannot be overlooked. These additional requirements are important for helping to improve the odds that the construction is not only resistant to bushfires but is also resilient enough to survive.

While most traditional building materials, such as timber are not prohibited in these areas, the building materials must instead be able to meet the flame exposure and radiant heat requirements of the Australian Standard AS 1530.

The Performance Requirement P2.3.4 of Volume Two (Class 1 and 10 Buildings) of the National Construction Code (NCC) requires a Class 1 building or a Class 10a building constructed in a designated bushfire prone area to be designed and constructed in such a manner that it will reduce the risk of ignition from a bushfire, with regard to:

1.the potential for ignition caused by burning embers, radiant heat or flame generated by a bushfire, and

2.the intensity of the bushfire attack on the structure.

In addition, AS 3959 divides bushfire prone areas into six bushfire attack levels (BAL). Victoria has now developed on-line Bushfire Prone Area (BPA) maps. The bushfire prone areas have been determined using the most recent available scientific information and data.

Every new home built in Victoria that is within a bushfire prone area must undergo a BAL assessment as part of the application for a building permit. The relevant building surveyor will use the BAL to check compliance with the construction requirements of the Standard.

While BAL-LOW areas are not subject to specific bushfire construction requirements, higher BAL areas are subject to compliance. AS 3959-2009 should be consulted for in-depth guide to permitted building materials for all BAL's.

What Is Ligna Stone?

Ligna Stone is a sustainable building product that is handcrafted using the patented Timbercrete blend of sand, timber waste (sawdust), cement binder and other non-toxic materials. The result is a distinctive product that offers many benefits over traditional clay and concrete equivalents, especially when it comes to offering resistance to bushfires for buildings and homes. Ligna Stone blocks are non-flammable and have been formally tested by CSIRO demonstrating them to be highly fire resistant.

Made from up to 70% wood waste, Ligna Stone is robust and durable making it less prone to breakages. In addition to the high fire resistance, it provides superior thermal insulation while being 30-40% lighter than clay or concrete.

Highly versatile, the Ligna Stone matrix can also be moulded into virtually any size and texture limited only by mould design. Colour variations are practically limitless and achievable through using oxides or different sands. Further, the Ligna Stone matrix can be altered to customise the performance of the product, making it suitable for a wide range of building applications.

How Ligna Stone Products Can Help Protect Buildings from Bushfires?

Late 2015 Ligna Group was recoinised by The Bushfire Building Council of Australia (BBCA). The BBCA promotes innovative building design, retro-fit products and whole community solutions, which are designed to improve Australia's resilience to bushfires. As the inaugural Product Innovation of the Year winner, Timbercrete was selected for its degree of innovation, affordability, and community benefit.

Ligna Stone using the Timbercrete matrix provides a single skin masonry wall system that exceeds the highest standard of FRL of 240/240/240 in load bearing applications. The product’s superior thermal insulation quality reduces the transfer of heat and provides a safer environment within the building. The high fire resistance makes it highly suitable for BAL FZ areas. Double brick blocks made using Timbercrete have also been used for BAL FZ areas.

In addition, Timbercrete products have already been put to the test during the recent Lancefield fire in Victoria. According to Tony Rule of Ligna Group, “a customer contacted us shortly after the fires in 2015 to tell that their A home constructed of our highly fire-resistant masonry product survived intact, whilst the remaining 40 Ha property was burned out. They believed our blocks played a major role in preserving their home during the fire. This is not an isolated event. We have heard similar stories in the Blue Mountains in NSW as well.

Unlike conventional building materials, Ligna Stone is a genuine environmentally friendly building material. It reduced impact on the environment and ability to permanently sequester carbon dioxide for the life of the product, sets it apart from clay bricks and concrete blocks.

Get in Touch

Ligna Group are the manufacturers and distributors of Timbercrete and Ligna Stone sustainable building materials. For more information on our products call us on +61 3 9758 9359 or send an email to tony@lignagroup.com