*ARCHIVE* - Weathertightness News - No. 5, Jan/Feb 2004
What's inside
- WHRS data highlights leaky building issues
- Weathertight Homes Resolution Service - latest figures
- Changes for timber treatment and balconies, decks and balustrades
WHRS data highlights leaky building issues
Adrian Bennett, currently seconded to the BIA from BRANZ says the Weathertight Homes Resolution Service (WHRS) data, as analysed by the BIA, highlights some contributing factors in the leaky building issue.
One of the more significant findings from the WHRS data is that stucco is significantly overrepresented in leaky building cases assessed by the service compared to its presence in the base population. Stucco stands out as the most common cladding in more than 200 leaky buildings assessed by the WHRS to October.
The data showed that 82 (38 percent) leaky buildings had some stucco cladding, with 65 leaky buildings having only stucco cladding. In contrast, surveys of new buildings over the last three years carried out by BRANZ suggested that stucco claddings were used in about six percent of houses.
Buildings using more than one cladding were common with 21 percent having more than one cladding material.
The second most common cladding used in the WHRS sample was textured fibre cement. It featured in 69 of the buildings inspected. The third most common cladding was EIFS cladding with 39 occurrences.
Conventional claddings, such as brick veneer, were less likely to appear in the WHRS data particularly as the sole cladding. Only two cases out of 211 had brick veneer as the sole cladding, with another eleven having brick as one of the claddings present in the building.
Horizontal timber weatherboard as the sole cladding featured only three times, while a total of 25 leaky buildings had timber weatherboards as one of the claddings. While buildings with monolithic claddings featured predominantly in the WHRS sample, it is also important to focus on what caused leaks and where they occurred. Most leaks do not occur in the body of the cladding but at junctions and penetrations. Thus buildings that feature more junctions and penetrations might be expected to have a higher likelihood of leaking.
This is clearly evident in the WHRS data, with 74 percent of houses having decks or balconies. Yet only roughly 14 percent of houses built in Auckland over the last three years had decks and balconies. Decks and balustrades were the most common sources of leaks reported by the WHRS assessors, with cap flashings (used on balustrades and parapets) the next most common source of leakage.
The increasing size and complexity of buildings mean more junctions and penetrations, and we might expect these buildings to be more common than simple single storey buildings in the WHRS data. In fact, two storey buildings made up the majority of the WHRS cases, followed by three storey buildings. Single storey buildings were present but at a much lower rate compared to the number of single storey buildings built.
It is hard to measure and record the complexity of building envelopes but some measure can be obtained from the summary sheets used by the WHRS. The WHRS data showed that 42 percent of cases had either a complex or highly complex wall shape and 37 percent of WHRS cases had complex roofs.
The presence of eaves on a building provides some protection to walls from rain. Reducing the eaves width allows more water to get to sensitive areas such as penetrations and junctions. Many modern house designs favour little or no eaves cover. It is perhaps not surprising that 50 percent of the WHRS cases had eaves of 100mm or less.
The Government set up the WHRS in late 2002 to assist homeowners with leaking buildings to identify the problems with their homes and reach a settlement with relevant parties (for more information see www.dbh.govt.nz).
As part of the process, an assessor inspects each building and compiles a report on the leaks and their causes. A summary of this data is entered into a database. From time-to-time this summary is made available to BIA and industry for analysis to help identify areas of concern.
It is important to note that the statistics relate to a small number (211) of the total claims (2,143) received by the WHRS at 30 October 2003. Data was supplied by individual assessors and, in all but a few cases, was not tested in the resolution process. In some cases data entries were incomplete. Because of these factors, the WHRS information must be considered as indicative only, and more a measure of emerging trends.
Weathertight Homes Resolution Service - latest figures
In early February, the Weathertight Homes Resolution Service (WHRS) had 1,685 active claims.
A reassessment of Weathertight Homes Resolution Service (WHRS) figures shows that fewer homeowners want to proceed with claims than previously thought.
Until recently, the number of claims reported by the WHRS included those from bodies corporate made in respect of all the unit owners in multiple dwelling complexes. The WHRS Act states that claims can only be accepted from the owner of the affected dwellinghouse.
WHRS had taken time to contact all the individual unit owners covered by body corporate claims to establish exactly how many people wanted to proceed with individual claims. At February 12, 2004, WHRS had 1,685 active claims and was continuing to receive more applications every month.
The WHRS had completed 55 resolutions: 38 using mediation, two through adjudication and 15 resolved by other means. The mediation and adjudication processes were underway for a further 134 homeowners. An additional 78 homeowners had their cases deemed eligible by the WHRS evaluation panel and had yet to decide whether to proceed to mediation or adjudication.
Assessments to determine eligibility for the service and the extent of property damage are provided at no cost to homeowners. If claims are eligible homeowners can choose to use the WHRS's voluntary mediation process, opt for compulsory adjudication, or decide to take no further action. Homeowners are required to pay $200 towards the cost of mediation and $400 towards the cost of adjudication.
The WHRS freephone help line 0800 116 926 operates Monday to Friday from 8.30am - 7.00pm. To date 5,765 calls have been received. Homeowners can also access the WHRS through www.dbh.govt.nz which contains information about the work of the service and issues related to leaky homes.
Changes for timber treatment and balconies, decks and balustrades
A recap of the BIA's changes for timber treatment and balconies, decks and balustrades.
The revised Acceptable Solution for Clause B2 Durability to the Building Code (B2/AS1) requires higher levels of timber treatment to parts of buildings more at risk from leaking. It comes into effect on 1 April 2004, subject to industry feedback.
The revised durability requirements recognise there is always a risk that a building could leak at some stage in its life. The timber durability and treatment requirements buy time to enable repair before structural damage occurs.
A particular risk associated with the weathertightness problem has been the potential of timber used in the construction of balconies, decks and balustrades rotting and collapsing with potentially catastrophic effect.
The revised B2/AS1 introduces an important change to the requirements for treated timber used when constructing buildings decks, balconies and balustrades. This is an increase in treatment level from H1 to H3.1 for all framing and boundary joists or walls for enclosed decks, balconies and balustrades. And, in some cases, the framing that supports the deck or balcony.
In August last year the BIA prompted territorial authorities to play a role in alerting property owners and occupiers to the potential risks with balconies and decking structures that relied on timber beams for structural support.
Enclosed balustrades that can rot from the inside, balcony floors that don't drain properly and balconies supported by untreated kiln-dried timber are among the types of structure considered to be at risk.
Building professionals and owners should take the issue seriously, given that potentially dangerous problems can remain hidden behind cladding. People with such balconies or balustrades should seek advice from a properly qualified professional.
Risks
If you have a balcony, consider these questions:
- has untreated kiln-dried timber been used for structural support?
- is the building clad with lightweight materials with a plaster finish?
- does water puddle on the surface rather than drain away?
- are there any holes or cuts in the balcony floor surface?
- is it on a split-level or two or three storey house or a multi-storey apartment building?
Look at the balustrade:
- is it clad with lightweight material with a plaster finish?
- does it have a flat top where water sits?
- does it have a railing where water is able to leak down screw holes?
Warning signals
- balconies that move usually when walked on.
- damp spots or stains where the balcony joins the main part of the building.
- cracks, particularly near joints and corners.
- balustrades that wobble.
- balustrades where damp spots or stains can be seen on the cladding.
The BIA recommends concerned property owners seek advice from a qualified expert as soon as possible.
For more information:
BRANZ
Ph 0900 59090 or www.branz.co.nz
Institute of Building Surveyors
Ph 0800 113 400 or www.buildingsurveyors.co.nz/
Weathertight Homes Resolution Service
www.dbh.govt.nz
Legality of BIA Interpretations
Only the courts can issue binding interpretations of the Building Act 1991 and Regulations. Indications and guidelines issued by the Department of Building and Housing, either in Weathertightness News or other communications, are provided with the intention of helping people to understand the legislation. They are, however, offered on a “no-liability” basis, and, in any particular case, those concerned should consult their own legal advisers.
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Published by the Department of Building and Housing ISSN 1176-3159. Print run: 11,000