Fireproof plywood rating up in smoke

Discrepancies in testing results should not be swept under the carpet, writes Matt Shand.

Another fireproof plywood product with a top New Zealand firerating has been found to be much less flame-resistant after retesting.

Hush Panels’ Radiata Plywood panels are rated as having a 1S fire-rating if coated in a Torchguard Lacquer. This rating means the product is less likely to easily ignite and in a building where it is used, occupants will have enough time to get to safety.

However, samples purchased and sent to the Building Research Association of New Zealand (Branz) returned a Group 3 rating for the product, which meant its fire-retardant qualities were significantly lower than had been previously stated.

Hush Panels declined to comment on the recent findings but said internal inquiries with suppliers were under way.

The Sunday Star-Times revealed this month how another high-end fire-safe radiata plywood, manufactured by Decortech, was found also to have returned a Group 3 rating after being retested.

Projects listed on Decortech and Hush Panels websites include public buildings such as hospitals, schools and theatres.

Samples of both products were purchased by a third party who doubted the claims and sent the products to Branz to be retested.

Industry insiders revealed there are many variable factors in the tests administered by Branz to determine the fire-ratings. For example, if a product received a 1S result, it would not have to be retested for five years regardless of whether the quality of the product had deteriorated over time.

Society of Fire Prevention Engineers New Zealand president Michael James said a drop from Group 1S to Group 3 was considerable.

‘‘I think it’s important when things like this come up they are not swept under the carpet,’’ he said. ‘‘As fire engineers, we take care of these things. Our members have been made aware there may be some questions about a product.’’

Branz spokesperson Sandy Rademeyer said the organisation ‘‘does not hold regulatory responsibility, nor does it act as a watchdog or enforcement authority’’.

If it had concerns it would contact the relevant client, and if there was a risk to public safety it would take further action.

A spokesman for MBIE said there was insufficient evidence to continue with an investigation into the named products but would look at further information.

‘‘It’s important when things like this come up they are not swept under the carpet.’’ Michael James Society of Fire Prevention Engineers NZ