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Weathertightness guidance resources

These resources have been prepared by the Department as guidance information in accordance with section 175 of the Building Act 2004. They are not Compliance Documents. They are intended to provide general guidance only to designers, building consent authorities (BCAs), builders, and so on.

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Dealing with timber in leaky buildings

The purpose of the guide is to provide practical advice on dealing with decayed timber that is found once the cladding of a leaky building is removed. Topics covered include:

  • Repairing a leaky building
  • Types of decay
  • Removing decayed timber
  • Health and safety issues
  • Site applied preservative treatment
  • Other sources of information

While primarily targeted at builders, Building Consent Authorities and building professionals, homeowners may also find the information useful.

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Weathertightness: Guide to remediation design

Focuses largely on the aspects that are particular to weathertightness remediation rather than the usual design process. The aim is to have designers appreciate the differences between designing repairs to leaky buildings and other design jobs such as additions or new builds.

While primarily targeted at designers who are either already undertaking this type of design work or, are considering taking it up, BCAs, builders and homeowners may also find the information useful.

The guide is a joint publication from the Department of Building and Housing and BRANZ Link to the BRANZ website.. It was developed with extensive input from practitioners and other experts from the building sector.

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Weathertnightness: Guide to the diagnosis of leaky buildings

Sets out current good practice for assessing leaky buildings. It covers the tools and techniques available to assessors and how to clearly and logically display their findings and conclusions in a report.

It is targeted at those who carry out detailed inspections of leaky (or potentially leaky) buildings.

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Weathertightness design principles

The principles of weathertightness design that have helped shape the Acceptable Solution E2/AS1 are explained in the guidance document External moisture – An introduction to weathertightness design principles.

The document provides a valuable summary of critical performance components for effective cladding systems and sets out principles that act as a checklist for performanced based designs outside the Compliance Documents. Knowledge of the principles of weathertightness is considered essential reading for all designers and builders of small- to medium-sized buildings, for building officials, educators and those with a general interest in weathertightness such as insurers, developers and funders of building projects.

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Risk matrix guidance

External moisture – a guide to using the risk matrix is a guide to understanding and applying the risk principles within the Acceptable Solution E2/AS1, and includes a series of three fully worked examples. The risk matrix can be used, with nominated cladding types and the associated inclusion of a drained and vented cavity in higher risk situations, as an approved means of achieving weathertightness. Building officials, designers and builders will find the information useful in identifying individual features that will require particular care and attention during design and construction.

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Constructing cavities for wall claddings

Constructing cavities for wall claddings. This practical and easy-to-follow guide explains drained and vented cavity construction for timber-framed buildings, as described in the Acceptable Solution for Building Code Clause E2 External Moisture, E2/AS1. It is designed to help those involved in design, construction and weathertightness compliance understand cavities to help ensure buildings are well built and healthy.

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Timber Treatment: Builders' Notes

Timber Treatment Requirements: Notes for Builders is designed as a quick guide to the general use of treated radiata pine and Douglas fir in buildings where buildings have been designed to the provisions of the Standard for Timber and Wood-based Products for Use in Building NZS 3602: 2003 (cited in B2/AS1).

The booklet helps builders understand what is the right level of treated timber in the most common situations and includes how to identify timber treatments and which type of treated timber needs to be used where. There is also important information on the safe handling of treated timber, as potential health risks are associated with some timber treatment preservatives.

This is an abridged outline to the full standard NZS 3602 and is to be used for guidance only. Anybody who produces, sells or specifies timber should obtain full copies of the relevant New Zealand Standards.

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Monolithic claddings assessment guide

Critical Requirements for the Assessment of 'Monolithic' Claddings (April 2004) was developed in conjunction with industry groups and the Building Officials Institute of New Zealand (BOINZ) to support the assessment processes and decision-making of building officials and building certifiers.

The guide contains:

  • an overview of the general principles to keep in mind while assessing whether or not a cladding system should be accepted as meeting Building Code requirements
  • guidelines for processing and inspecting a building consent application for:
    • solid plaster (stucco)
    • fibre-cement sheets coated with modified plaster/paint systems
    • EIFS or polystyrene sheets coated with modified plaster/paint systems
    • guidance on how to inspect monolithic cladding systems already installed.

The guidelines are a reference tool for skilled professionals who have an understanding of the Building Act, the Building Code, assessing alternative solutions and monolithic claddings, along with processing building consent applications, and carrying out building inspections.

It is important to point out that the guide is not a Compliance Document. It is intended that building officials use the publication as a basis for comparison with the existing processes used within their organisations, and to gauge whether or not their assessment procedures are robust enough, in light of that comparison.

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Building A-Z

The building A-Z glossary covers commonly-used terms in the industry, with the focus on terminology used in the regulation of building work in New Zealand.

Its purpose is firstly to give a definition of the term. Where possible, definitions are repeated from core regulatory documents, such as the Building Act and Building Code, but with rewriting in some instances to make the terminology more accessible to people without industry experience. The second purpose of this A-Z is to provide links to further information either on the Department of Building and Housing’s website or on other sites.

It is not a comprehensive glossary of all the building-related terms you might come across. Other glossaries are available, for example Consumerbuild Link to ConsumerBuild.

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