Home Learn LBP & Regulation USING TIMBER JOINERY CORRECTLY

April 2020

USING TIMBER JOINERY CORRECTLY

16 Mar 2020, LBP & Regulation, Learn, Prove Your Know How

Timber joinery is a feature of New Zealand heritage architecture and is a relevant part of building and renovation today, but it’s important to know how and when to use it

Timber joinery products meet the requirements of the current Building Code, but there are several Standards to consider, so it’s important to use them accordingly. The following tried and trusted standards can give you confidence that you are following good practice.

Benefits of timber joinery

Timber joinery provides many benefits:

  • Higher thermal resistance compared to some commonly used building products.
  • Condensation is reduced or eliminated with double-glazed timber joinery.
  • Joinery details that closely mimic the traditional appearance of timber joinery allow replacement and renovation work to blend seamlessly.
  • Surface coatings that can be repaired relatively easily on site and colours that can be changed to suit the client’s needs.
  • Added design flexibility due to the relative ease in modifying timber profiles.
  • Reduced carbon footprint, as the product is manufactured from renewable timber resources and, with the proper maintenance, it can last 50-plus years.

Specify the right product for your job 

In New Zealand, testing the weathertightness performance of individual windows and doors for external use is done using NZS 4211:2008 Specification for performance of windows. This standard also includes glazing systems.

Windows and doors that pass NZS 4211:2008 testing can be labelled as being in accordance with NZS 4211:2008. This includes the appropriate air leakage and wind zone rating for the product, as established through the  testing.

Generally, when specifying windows and doors using NZS 4211:2008, the following steps should be taken:

  1. Establish the appropriate wind zone in accordance with NZS 3604:2011 Timber-framed buildings section 5.
  2. If the wind zone is beyond that given in NZS 3604:2011, see section 10 of NZS 4211:2008.
  3. Select a window that has been tested to NZS 4211:2008 and is labelled as suitable for the relevant wind zone.

In May 2014, the wind zones in NZS 4211:2008 were revised to align with the wind zones specified in NZS 3604:2011. This incorporates the extra-high wind zone for more exposed building sites.

Some NZS 4211:2008-compliant timber joinery suites have been tested beyond the extra-high wind zone, so specifying these can give you additional confidence in performance.

Easy to identify NZS 4211:2008-compliant joinery

It is easy to tell the difference between NZS 4211:2008-compliant timber joinery and other timber joinery. NZS 4211:2008-compliant joinery will be fitted with identification tags that show relevant wind zone and air leakage ratings. See example of NZS4211:2008-compliant timber joinery tag below:

It also has a unique identification number that can be traced back to the original registered manufacturer. Tags are typically installed on the frame in the rebate of an operable door or window sash, like those found on fire doors.

Registered manufacturers of NZS 4211:2008-compliant timber joinery must work to a manufacturing standard to ensure quality. Structural members within the joinery are individually calculated using specialist software and engineered calculation charts. Timber species and size can be altered to ensure relevant wind zone requirements are met.

More information online 

NZS 4211:2008 is one of the standards funded by the Ministry of Business, Innovation and Employment (MBIE) to support Building Code compliance. The NZS 4211:2008 standard can be downloaded free of charge on the Standards New Zealand website.

NZS 4211:2008-compliant timber joinery product and installation details can also be downloaded from the Joinery Manufacturers’ Federation website.

The documents available on the website outline opening trim preparation, flashing details, fixing methods and seal locations. They will assist in both detailing and installing timber joinery to appropriate standards.

This article is an excerpt from Codewords Issue 94. Reading Codewords articles that are relevant to your licence class is a mandatory requirement for Licensed Building Practitioners. These questions can be answered through the LBP portal, online at underconstruction.placemakers.co.nz or recorded on the magazine, then provided at the time of renewal.


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3 Comments

  1. precisionfitouts@gmail.com says:

    Good quiz

  2. dpmal@slingshot.co.nz says:

    Check specifications

  3. jimpember51@gmail.com says:

    windy everywhere, check area.

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