Law firm says it has more than 500 potential claimants for leaky homes class action against James Hardie

Law firm Parker & Associates says it now has more than 500 potential claimants for its leaky homes lawsuit against James Hardie Industries, transforming the case into a class action against the maker of Hardiflex cladding.

The Wellington-based law firm first filed a claim in the High Court in August on behalf of Tracey Cridge and Mark Unwin, alleging James Hardie was negligent in its design, manufacture and supply of the Harditex cladding system, while calling for other claimants to join the suit. James Hardie has vowed to "vigorously defend" the allegations.

The 'Cladding Action' case would be New Zealand's first leaky homes class action, the law firm said. Claimants were now moving quickly to officially opt in, it said.

A second plaintiff class of owners of properties clad in James Hardie's Titanboard product is also being assembled to be added to the claim, it said.

Lawyer Dan Parker said that water damage as a result of the alleged issues with Harditex are often not immediately obvious to homeowners. His firm's media release cited lead plaintiff Scott Woodhead who had gone unconditional on his first home in August before discovering problems.

"The house looked in very good condition and two building reports made no mention of issues with the cladding," he said. "After speaking to my neighbour I got experts to explore the problem and was horrified to find toxic mould is present under the cladded surface. That is when I decided to join the Cladding Action."

Parker & Associates said owners of leaky homes should investigate whether Harditex cladding systems had been used in their house before a Dec. 31 cut-off "after which there will be a bar on claims based on acts or omissions that occurred more than 15 years ago, when many Harditex properties were built."

The class action is the second over potential leaky homes this year after Adina Thorn Lawyers launched one against plaster cladding manufacturers, and follows a Court of Appeal ruling that a Ministry of Education's claim against Carter Holt Harvey isn't subject to a 10-year limitation under the Building Act.

New Zealand has yet to develop legislation for class actions, with representative suits evolving through court rules rather than legislation and leaving a lack of clarity around some of the procedural rules, which can lead to protracted litigation.

The government had expected to complete the policy work for the legislation in 2012, adopting one of the recommendations in a parliamentary select committee report into the spate of finance company collapses through the second half of last year, but has since put the work on the backburner.