BRANZ Guideline July 2012

Issue 41 – August 2012

BRANZ seminars August 2012 – internal moisture

High moisture levels in our residential buildings are a significant problem in New Zealand, particularly as buildings have become more airtight and occupants are less likely to leave windows open. This seminar aims to give practical design and construction advice that is based on research for New Zealand conditions to ensure that internal moisture does not continue to be a significant problem.

Stud substitutions

In NZS 3604:2011Timber-framed buildings Table 8.2 (Studs in loadbearing walls for all wind zones – SG8), Note 2 states that 140 x 45 mm framing may be substituted for90 x 90 mm framing. This means that 140 x 45 mm can be used instead of 90 x 90 mm,but90 x 90 mm cannot be used instead of 140 x 45 mm.

Related Standard

Roof/ceiling space ventilation units and gas central-heating units

AS/NZS 5261:2003 Gas installation does not permit the installation of home ventilation units into a roof or ceiling space that has a gas central-heating unit installed within it because it may interfere with the safe operation of the gas appliance. Conversely, if the home ventilation unit is already in place, the gas unit will need to be located elsewhere or the ventilation unit removed.

Related Standard

Concrete finish to exposed foundations

NZS 3604:2011Timber-framed buildings requires that the surface finish of foundation walls exposed to the weather complies with NZS 3109:1997Concrete construction, which, in turn, references NZS 3114:1987 Specification for concrete surface finishes, which gives the finish options that can be used, such as F3.

What this means is that designers should specify the finish required in the contract documents. If this is not done, builders should identify in their quote or tender the level of finish they have allowed for.

Related Standards

Decks close to ground

When constructing decks close to the ground, NZS 3604:2011 Timber-framed buildings does not allow H5 piles to be cut or drilled (for example, for fixings) within 150 mm of the finished ground level.

Related Standard

Summarised from BRANZ Guideline, July 2012.


Published in building.