Publication

Amendment

Bulletin 457 Ventilation of enclosed subfloor spaces

Note that, while E2/AS1 only requires ventilation under suspended timber floors, BRANZ recommends as good practice that ventilation is also designed for under suspended concrete slab floors.

Bulletin 472 Waterproof
decks

Download Bulletin 472 supplement.

Bulletin 478 Rainwater collection for domestic use

Download Bulletin 478 supplement.

Bulletin 481 Timber windows

Download Bulletin 481 supplement.

Bulletin 485 Domestic on-site wastewater systems

Bulletin 495 Stair design

Figure 6(b) - The tread dimension should read 266 to give a 35º pitchline. Figure 6(c) - The pitchline for the dimensions given should be 31.85º and not 33.1º as noted.

Bulletin 498 Preparation for concrete floor slabs

Paragraph 12.0.2 of this bulletin refers to shrinkage control joints and states that: "Mesh reinforcing to the slab must stop each side of the joint." This is not correct - stopping the reinforcement each side of the joint creates a ‘free joint', not a shrinkage control joint. The mesh in a reinforced concrete slab on ground should not be cut when cutting/forming a shrinkage control joint. See Build 84 Oct/Nov 2004 p35 for more information.

Bulletin 515 Measuring moisture in timber and concrete

In the first issue of this bulletin, the corrected moisture content percentages for boron-treated radiata pine given in Table 2 were wrong. The correct figures are:

The bulletin also gives an allowable moisture content of 24% for framing timber in uninsulated buildings. The figure is now 20% for all timber framing before internal linings are fixed. (Note that a lower moisture content may be required by manufacturers whose product is fixed to the timber).
The bulletin also gives an allowable moisture level for timber weatherboards and exterior joinery of 20% at the time of painting. In fact, the 20% applies at the time of installation.

This bulletin refers to NZBC clause B2 Durability, and states in paragraph 4.1.2 that: "The main roof components must be provided with a durability of not less than 50 years." Where a green roof system is designed so that it is considered moderately easy to repair/replace the waterproofing system (by removing the growing medium), it is believed that a durability that is equal to the serviceable life of the garden system, but not less than 15 years, would be appropriate for the waterproofing system. A durability of not less than 50 years would still apply to the supporting structure.
A durability of not less than 50 years is, we believe, appropriate for a waterproofing system that is difficult to access for repair and/or maintenance. Factors that would influence this include ease of access on to the roof, height of the roof and the depth of the growing medium.

Table 3 gives the wrong preservative ID number for propiconazole and tebuconazole, and no number for permethrin. The correct ID number for propiconazole and tebuconazole is 64, and the number for permethrin is 70.

Bulletin 541 Concrete floor slabs

Amendment 11 to compliance document B1/AS1 requires the use of grade 500E mesh for concrete slab-on-ground reinforcing. This change applies to slabs on ground being built to NZS 3604:2011, NZS 4229 and NZS 4299. Bars within the foundation must also be ‘E' type steel to ensure they have sufficient ductility but may be either grade 300E or grade 500E. Paragraph 4.6.1 of Bulletin 541 incorrectly asserts that all steel bars within the foundation wall must be grade 500E.

Bulletin 542 Key changes to B1/AS1 and E2/AS1

This bulletin has been withdrawn. An updated version will be published as Bulletin 545 in February 2012.

Good Practice Guide: Internal Lining

Download 2008 update supplement.

Good Practice Guide: Profiled Metal Roofing

The maximum permitted area of roof (in m²) discharging to a given downpipe size given in Table 11 is significantly different from that specified in E1/AS1. This may result in the downpipe being overloaded in maximum rainfall conditions. Please delete Table 11 and replace with Table 5 of E1/AS1. Figure 3 of E1/AS1 may also be used to assist in sizing downpipes for given flow rates.
Some of the illustrations also show an old practice of running insulation blanket over the purlins and immediately under the metal roofing. With this construction, there is a risk that the insulation will absorb condensation and become damp, which may cause corrosion to the underside of the roofing metal. The illustrations are on page 11 (top right), 17 (centre right), 19 (Figure 1), 33 (top right) and 64 (centre left). As more recent BRANZ publications show, roof underlay should come between the profiled metal and the insulation. There should be a minimum 25 mm air gap between the the underside of flexible roof underlay and the insulation.
A new edition of this book is currently in preparation.

Good Practice Guide: Tiling

On page 48, BRANZ recommends a fall of 1:60 for shower bases. Note, however, that in Acceptable Solution E3/AS1, clause 3.35 states:
"Where the shower floor has no upstand or where a wall, screen, door or curtain is omitted, the floor shall have a fall of no less than 1:50 towards the floor waste."

Good Practice Guide: Timber Cladding

For Figure 19 on page 29, the minimum lap for bevel-back weatherboards should be 32 mm (E2, NZS 3617:1979 Specification for profiles of weatherboards, fascia boards, and flooring).

Guideline - November 2006

Download November 2006 update.

Guideline - January 2011

House Insulation Guide (4th edition)

On page 13, the last paragraph should read: "The calculations in this guide are based on steel framing which is 89 mm deep and 40 mm wide. If 32 mm framing is used, the thermal bridging will decrease. To account for that in our tables and graphs, use the construction with a 20% lower framing ratio. For example, for walls with 40 mm wide studs at 400 and dwangs at 1200, the framing ratio is 14.5%. If you wish to specify 32 mm wide studs at 400 and dwangs at 1200, use the R-values given for studs at 600 and dwangs at 1200 (a framing ratio of 11.4%). The R-value for 32 mm wide studs will be R 0.1-0.2 greater than the values listed for 40 mm wide studs.
On pages 95-104, the calculations for the steel framing are based on steel 40 mm wide by 89 mm deep. See comment above if you wish to specify 32 mm wide framing.
On pages 110-113, the wording under the horizontal axis of the graph should read "Insulation material R-value".
On page 114, in the first column of the table, the last construction listed should be "Plain slab with 90 mm stud wall". 

Landscape Construction

Download correct version of Figure 23 on page 55. This amendment applies only to copies with the BRANZ logo on the front cover of the publication.

Selecting Timber (3rd edition)

Sprinklers for Houses

Download August 2006 supplement.

Weathertight Solutions Vol 2: Stucco

All head flashings detailed should incorporate stop ends, because stucco is installed over a cavity. The stop ends have been omitted in drawings 2.1.1.1, 2.1.2.1, 2.1.4.1 and 2.1.5.1.

Weathertight solutions details

The DWG/CAD file for WSD 2.1.14.2 Stucco DIRECT-FIXED VERTICAL SHIPLAP WEATHERBOARD JUNCTIONS External corner - vertical shiplap weatherboard - limited risk score is incorrect in existing versions of the stucco collection CD and was incorrect as a download from this website before 18 January 2010. Download the correct version of 2.1.14.2.dwg.