BRANZ Guideline September 2011

Issue 32 – October 2011

Misuse of BRANZ appraisals

Building Consent Authorities and product specifiers need to be aware BRANZ Appraisals only relate to the specific product for the specific use defined by the Appraisal. BRANZ Appraisals for Juken Strandboard Flooring and/or The Laminex Group Strandfloor are being used by other organisations to verify the NZBC durability requirements of oriented strand board products from other manufacturers for uses other than flooring, specifically the webs of composite timber I-beams. Read more in the BRANZ Guideline September 2011 [PDF 157 KB].

Timber treatment

Vigilance is required when checking or purchasing treated timber. BRANZ has been made aware that some timber previously treated to H3.1 (which had 'H3.1'and 'keep dry' markings on the timber) is being 'retreated' to H3.2 specification but retains the H3.1 markings. Read more in the BRANZ Guideline September 2011 [PDF 157 KB].

Floor diaphragms – T&G edged sheeting

The manufacturer's specific fixing requirements must be followed for sheet flooring materials with a nylon tongue jointing system that are used as a floor diaphragm. Read more in the BRANZ Guideline September 2011 [PDF 157 KB].

Timber-framed chimneys

There is increasing use of metal flues installed within timber-framed chimneys in new building work and where an existing brick chimney has been removed to roof level. A number of specific requirements need to be incorporated into their design and construction. Read more in the BRANZ Guideline September 2011 [PDF 157 KB].

Insulation

BRANZ is still seeing poorly installed wall and ceiling insulation with gaps and folds that significantly reduce the effectiveness of the insulation. There is no point in the client paying for higher R-value insulation if it is poorly installed and the benefits are lost. Gaps around the edge of the insulation can reduce the effective R-value by around 3% for every 1 mm of gap. This means if you have gaps of, say, 16 mm, the R-value of the installed insulation is approximately halved.

Glazing

BRANZ has received calls again about unmarked glass being supplied for areas where safety glass is required. In one case, the BCA inspector who identified the lack of markings was told that the supplier will put whatever marking they require on the glass. Clearly, this is not a reputable supplier. Using a supplier who is a member of the Glass Association of New Zealand (GANZ) is recommended. Read more about minimum marking requirements for safety glass in the BRANZ Guideline September 2011 [PDF 157 KB].

All information on the use of safety glass where human impact is likely is given in NZS 4223 Part 3. For more information and if in doubt, contact a GANZ member.

Related Standards

BRANZ seminars on B1/AS1 and E2/AS2 changes

Recently there have been some significant changes in the compliance documents for New Zealand Building Code (NZBC) clauses B1 and E2. BRANZ is holding seminars from October to December 2011 to describe the key changes to NZBC clauses B1 and E2.

Visit www.branz.co.nz/seminar_details for seminar dates and online registration.

Published in building.