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Update on the NZ Wood Design Guides

NZ Wood Design Guides Launch and Update.

The Wood Processors and Manufacturers Association (WPMA) in conjunction with Building Research Association of New Zealand (BRANZ), Timber Industry Federation (TIF), Timber Design Society (TDS), Engineered Wood Products Association of Australasia (EWPAA), Scion and Forest Growers Levy Trust (FGLT) represents the majority of New Zealand’s timber technical literature development. These organisations have grouped their resources to produce a comprehensive series of “One-Stop-Shop” Timber Design Guides to support the uptake of timber products in the construction industry.

The NZ Wood Design Guide project comes at a time when timber construction is pushing into commercial and multi-story buildings, as preferred material for prefabrication, seismic resilience properties, with strong environmental credentials and new construction techniques. It is an exciting time for timber with a lot of work yet to be done to realize the full potential of man’s oldest modern building material. The NZ Wood Design Guides project looks to provide a targeted suite of design guides to developers, engineers, architects, quantity surveyors, building consent officials and other professionals to enable the uptake of the new breed of engineered wood products and timber systems. Support for this project has been widespread across manufacturers, fabricators, professional service providers and construction companies, actively participating in the development of these guides to share current “standard” industry practices and current design thinking.

The first two available guides in this series of 54 guides “Design for Fire Safety” and “Designing for Prefabrication” are available for immediate download and use from the NZ Wood website: https://nzwooddesignguides.wpma.org.nz.

Three other guides are in the final stages of preparation and 10 new guides are in initiation development stages. Ultimately, these will be available via a cloud-based, searchable library along with a dedicated timber design centre. If you are involved in design of timber buildings these are a must for your library. Hard copies are available on request (at print and postage costs). For further information please visit www.wpma.org.nz.


Exert from the NZ Wood “Design for Fire Safety Guide”

“Because wood burns, many people assume that all timber buildings have poor behaviour in fires. However, where necessary, timber buildings can be designed with excellent fire safety for the occupants, and sufficient fire resistance to prevent spread of fire or structural failure.

Timber structures tend to fall into two distinct categories; “heavy timber” structures and “light timber framing”. Heavy timber structures are those where the principal structural elements are beams, columns, or panels made from sawn timber, glue laminated timber (glulam), laminated veneer lumber (LVL), or cross laminated timber (CLT). Light timber framing consists of timber stud and joist construction, typical of New Zealand house construction.

Large sized timber members, whether sawn timber or engineered wood products, have the inherent ability to provide fire resistance because surface charring of the wood allows an insulating layer to form that provides some protection to the underlying timber. In light timber framed structures, appropriate protective lining materials (e.g. gypsum plasterboards) can provide excellent fire resistance.

The contribution from timber building materials to the overall fire load depends on the surface area of timber exposed to the fire. With limited amounts of timber exposed, it is small compared with the contribution of the combustible contents which constitute the main fire load. However, a significant contribution will be made where large surface areas of timber walls or the underside of timber floors become involved in the fire.”


Exert from the NZ Wood “Designing for Prefabrication Guide”

“Essentially the question to be answered for the client is “what is the most efficient way to realise the project” given the project brief?

By better understanding prefabrication and the strengths of various timber systems on offer, designers and specifiers will be better equipped to come up with design solutions for their clients.

This Guide intends to achieve this in a two-pronged approach: Firstly, by educating readers about the most important prefabricated timber systems, their characteristics and applications, and secondly, by providing guidance on the collaboration and interaction between the various stakeholders throughout the prefab design and build process.

Prefabrication as a mode of construction is a relatively broad term and can refer to a whole spectrum of prefabricated components, from small individual components (pre-cut beams or posts), to closed wall or floor panels, to 3D volumetric modules or pods, through to completed prefabricated buildings or hybrids thereof. This guide will be relevant to the entire spectrum of prefabrication with the intent to sharpen designers understanding on what type of prefabrication is most relevant to their project.”

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