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Determinations issued

To date, 112 Determindations have been issued this year.  The following are summaries of Determinations issued recently.  To read Determinations in full, see the register.

Determination 2005/94

Issued 16 June 2005

In this case the owner disputed the council's decision not to issue a code compliance certificate for 5-year-old additions to a house and a separate garage ('the additions'), unless changes are made to their monolithic cladding systems to comply with the external moisture requirements (E2) and durability requirements (B2) of the Building Code.

The building work

The building work comprises additions at two separate locations to an existing single-storey house, and an end addition to a single-storey garage, both situated on a sloping site in a high wind zone. The house is of conventional light timber frame construction on a piled timber framed floor, with both the new and the existing external walls lined with new monolithic cladding. The resulting house is of a relatively simple shape with the pitched roof having valley junctions. The eaves have 600 mm and 1200 mm wide projections and, apart from the rear of the house, the verges have 400 mm wide projections.

Submissions/reports

The owner provided extensive information with their application. The territorial authority did not make a submission. An independent expert undertook an inspection of the building work. This report was reviewed by the Department's staff and provided to the parties.

Discussion

Key items were examined, which included the design of the building, the surrounding environment, the design features that are intended to prevent the penetration of water, the cladding system, its installation, and the moisture tolerance of the external framing.

Investigation found that the cladding appears to have been installed according to good trade practice and to the manufacturer's instructions, with no areas of concern. It can therefore be considered to be effective in preventing the penetration of moisture.

The performance of the cladding, despite the lack of a cavity, is assisted by a number of factors.

  • The cladding appears to have been installed according to good trade practice.
  • The house and garage are single storey and of relatively simple shapes.
  • The house has eaves and verge projections that afford good protection to the cladding under them.
  • There are no balconies.
  • The external wall framing is likely to be treated to a level that is able to resist decay if it absorbs and retains moisture.
  • There is no moisture evident in the external wall cavities at this time.

Decision

The house is weathertight now and therefore the cladding complies with Clauses E2 and B2 of the Building Code. The territorial authority's decision to refuse to issue the code compliance certificate was reversed.

Determination 2005/108

Issued 22 July 2005

This application arose from the refusal by the territorial authority to issue a code compliance certificate for a 1-year-old house because it was not convinced the cedar weatherboards would perform adequately to satisfy the external moisture requirements (E2) and durability requirements (B2) of the Building Code.

House design

The building work is a single-storey detached house, situated on a flat site, which has been calculated as being in a medium wind zone. The external walls are of conventional light timber frame construction built on a concrete floor slab and sheathed with cedar weatherboards. The house is of a simple shape, with a pitched roof with gable ends. Apart from the fascias, there are no eaves and minimal verge projections to one end wall. A colonial style 1600 mm wide veranda protects the other three walls.

The cladding system is imported cedar weatherboard secured with stainless steel divergent staples to vertical H3.1 treated battens that are fixed over a 'Pauloid' building wrap to form a 20 mm cavity. The building wrap is laid over a 9 mm H3 plywood substrate that is fixed directly to the framing.

Submissions/reports

Both the owner and the territorial authority made substantial submissions and provided additional information throughout the course of the application.

Discussion

Generally, the cladding appears to have been installed according to good trade practice, but there are some areas of concern.

  • The vermin proofing of the drained cavity.
  • The re-fixing of one board above the windows.
  • The application of a bead of sealant to the edge of the window and door jamb scribers.
  • The application of an additional coat of sealer to the weatherboards.

The factors that assist the performance of the cladding are that the:

  • cladding generally appears to have been installed according to good trade practice
  • house has wide veranda projections to three elevations that provide excellent protection to the cladding below them
  • house has cladding with a drained and ventilated cavity between it and the wall framing.

However, because the cladding faults on the house are likely to allow the ingress of moisture in the future, the house does not comply with the durability requirements of Clause B2.

Decision

The house is weathertight now and therefore the cladding complies with Clause E2. However, as a number of items need to be remedied to ensure it remains weathertight and thus meet the durability requirements of the Building Code, the house does not comply with Clause B2. The territorial authority's decision to refuse to issue the code compliance certificate was confirmed.