Extinguishing composite timber myths

The Grenfell Tower fire tragedy has ignited an unnecessary atmosphere of hesitation among architects regarding composite timber.

The tragic event in June claimed about 79 lives and has sparked a global concern about using cladding systems after it was found the cladding was in breach of UK building regulations and was blamed for the rapid spread of the blaze.[1]

The incident prompted the Australian building industry to scrutinise its own fire safety, with a senate inquiry being told that it could only be a matter of time before we see an Australian version of the Grenfell Tower fire tragedy due to Australia's lax building laws. The inquiry heard there are up to 2,500 buildings in NSW that may contain the non-compliant cladding similar to that which is being blamed for accelerating the Grenfell fire.[2]

Unfortunately, the event may have fuelled the myth that all composites are the same and timber composites are not fire safe. Some architects are shying away from its use based on the false belief that timber is an unpredictable and unsafe material. However, despite timber being combustible, rather than quickening the spread of a fire, it is a good insulator and burns in a predictable fashion. Related to this misunderstanding are concerns about the levels of plastic content in composite timber. Although the types of plastic typically used in the production of wood-plastic composites have higher fire hazard properties than wood alone, there are options that offer higher compositions of recycled wood. For example, Innowood offers extremely low VOC ranges made from up to 70 per cent of wood waste.

Another challenge facing the industry is a lack of clarity and understanding around fire standards in the existing building codes, causing confusion among stakeholders of all stages of the design process.

Composite timber can be fire safe, but like any product, it must be specified for the correct uses and in the right conditions. There is no need for architects to compromise on the aesthetic and warmth that a timber product offers a design due to fire safety concerns. When considering composite timber, architects simply need to ask the right questions.

Check the product meets the latest codes and standards

Choose composite timber products which undergo continual fire retardant and self-extinguishing testing, confirmed by updated and accurate fire testing certificates by NATA-certified laboratories.

Ask for proper documentation

All testing results and certificates should show compliance to Australian Standards and full product specifications, including fire details. The relevant standards which will show how composite timber products or materials behave in a fire are: AS1530.3 (Early Fire Hazard Test), AS/NZS 3837:1998 (Cone Calorimeter test – Heat & smoke release rates - Group number test) and AS 3959:2009 (Construction of Buildings in Bushfire Prone Areas).

Check if the supplier is up to date with the latest building code changes

Look for a supplier which is thorough in its testing. For example, Innowood consistently works with testing departments to understand the results and requirements of their composite timber products. The company also offers continual upskilling and education for staff on a range of topics, including fire-related requirements.

To find out more about specifying fire-safe composite timber products, check out this free whitepaper.