Engineered wood products a safe solution

Engineered wood products are increasingly being used for fire-protected timber construction following changes to the National Construction Code in 2019.

PAOLO LAVISCI

WoodSolutions

With the rapid growth of engineered wood products (EWPs) in Australia, it is important to understand how EWPs may be different to other building materials and systems, and what you should be aware of when assessing a timber project.

When we refer to EWPs, it includes all the wood-based products where there is some form of engineering and offsite prefabrication. Such products range from stud frames, I-joists and cassettes to mass-timber components such as crosslaminated timber (CLT), glue-laminated timber (GLT), laminated veneer lumber (LVL) and nail-laminated timber (NLT).

While risks are common across all building materials and systems, one of the perceived risks for timber mid-rise construction is fire safety, because timber is a combustible material. However, in 2019, the National Construction Code (NCC) introduced Deemed-to-Satisfy (DtS) solutions for fire-protected timber construction, up to an effective height of 25 metres.

Under these changes, fully encapsulated EWPs will behave like non-combustible materials for the prescribed fire resistance levels and the DtS provisions. In fact, EWPs have very predictable and well-documented fire behaviour, and they maintain their strength and stiffness when temperatures rise.

Performance solutions are required when structural timber is exposed, but professional fire engineers can apply the same approach as with any other exposed structure.

The precautions during construction do not differ significantly from what is applicable to other materials.

Understanding and designing for these factors is critical to demonstrating that a performance-based fire strategy will meet building code requirements, and has successfully been done in several cases for projects up to ten storeys (built) and 15 storeys (approved). In North America and Europe, even taller buildings have been completed (18 storeys fully in EWPs, including the core; 24 storeys in hybrid construction).

For information and test reports related to the NCC-compliant fire-safe design of timber buildings, visit www.woodsolutions.com.au/ publications.

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From fire test reports to Technical Design Guides, WoodSolutions has accurate, accessible information to help you meet the requirements of the National Construction Code and specify appropriate timber fire solutions for every situation. Visit WoodSolutions.com.au today or use the QR code to go straight to fire resources.