Risk Assessment: Why Engineered Wood Products Are Safe
By Paolo Lavisci, WoodSolutions
Although many hazards are common to all building materials and systems, it is important to understand how engineered wood products (EWP) may be different and what you need to be aware of when evaluating one. a wood project.
One of the perceived risks for mid-rise timber construction is fire safety. However, the timber construction achieves the performance required under the National Building Code’s Deemed Satisfactory Solutions (DTS) for fire protected timber construction up to an effective height of 25 metres.
In fact, PTEs have a very predictable and well-documented fire behavior and retain their strength and stiffness as temperatures increase. Understanding and designing these factors is essential to demonstrating that a performance-based fire strategy will meet building code requirements and has been successfully achieved in many cases.
Safety, speed and quality of construction
The use of elevating work platforms has been shown to improve site safety. Significantly high construction safety levels are the primary driver of installation efficiency and freedom from defects. But the quality cannot be controlled if it has not been designed, so it is important that the design resolution and conflict detection are completed before shop drawings and production. This is an easy task with elevating work platforms due to their precise dimensional tolerances, while minor on-site adjustments are very simple to make, if required.
While structural elements are fabricated off-site, on-site activities focus on the assembly of the structure and the speed at which it can occur. The analysis of the 26 projects in the WoodSolutions database reveals the following “average project” data: the wooden joinery of a 7-storey building, with a gross interior surface area of approximately 8,000 m2, is installed by a team of 7 people at a rate of 92 m2 per day. Of course, installation rates can vary and are very project specific, but in general terms they are significantly faster than with other materials.
Quality assurance is a simple task with EWPs, as highly automated processes are normally used, in which all materials are tested, recorded and tracked throughout the production chain. As with any other product, it is important that all items installed conform to the specified design.
In terms of financial risk, as the level of off-site manufacturing increases, suppliers may require a substantial deposit well in advance of delivery. But for PTEs, this can be offset by the time savings which, in most cases, mitigate this risk.
PTEs have historically shown less price volatility than other materials and, although a hot topic at the time of writing, there are already signs of lower future price indices. . Most analysts expect the associated supply shortage to soon begin to ease gradually, as the industry is already investing to improve capacity.
As wood-based projects require the design to be largely worked out before items can be produced, projects often experience less variation than is common with other materials which have larger tolerances and require more work on site.
Generally speaking, significant benefits can be found in a fast and predictable build process, where the accuracy of EWPs plays a major role.
WoodSolutions Fact Sheet #17 on Midsize Insurance is a useful reference that you can download.
For more information, expert advice, case studies and technical design guides, visit the WoodSolutions website https://www.woodsolutions.com.au
Images 1 and 2 – La Trobe student accommodation
Multiplex has completed the 624-room LaTrobe Uni student housing in Bundoora. Architect: Jackson Clement Burrows
Photographer: Glenn Hester
Picture 3 AVEO Bella Vista
The AVEO Bella Vista building, completed in Norwest, Sydney in 2018, breaks the mold of typical mass timber designs for residential buildings that we have seen internationally over the past decade.
Architect: Jackson Teece
Photographer: Brett Boardman