A class action lawsuit is alleging a major building product manufacturer never tested its product before selling it - and once they knew it wasn't up to scratch, continued to sell it.
More than 1000 people are collectively seeking more than $200 million in a court battle against the James Hardie group of companies.
It's a mammoth case - six years since the first legal claim, set down for four months, to in part determine one of the country's longest-running legal dramas - leaky homes.
Sharon Leigh and her husband are living in a mouldy, rotting home in Whitby, near Porirua.
"I have been told to move out of the house due to my health - it's not safe to be in there because I'm a chronic asthmatic and we have black mould," Leigh said.
She said the house would cost hundreds of thousands of dollars to fix, or they could sell for next to nothing.
They could not afford to move out; they still had a mortgage on the house, and leaving would mean another mortgage or renting elsewhere.
Leigh and the other plaintiffs are arguing building materials company James Hardie sold them faulty, leaky exterior cladding called Harditex, a product used on the outside of the house, and the first defence against the elements.
Their lead lawyer, Simon Hughes QC, said the cladding was "inherently flawed". It both allowed water in, and didn't allow it out, he said.
"Does Harditex work as a barrier cladding system - does it stop the water getting in? We say no. If the water ingresses, is there a designed facility for that water to get out, so there is no rot and damp? We say no, it doesn't do that either."
The legal action is under the Consumer Guarantees Act and the Fair Trading Act.
Hughes said the defence's case (which hasn't started yet) would say it was not the cladding at fault, but the builders - that bad workmanship was the problem.
Hughes said there were more than 300 buildings covered by the claim however, and a person would have to believe tens or hundreds of different builders made the same mistakes in construction.
"It is much more likely on an intuitive basis with a common set of problems that it is the product, the system, which is the explanation, and not the builders."
The claim outlines that James Hardie knew or ought to have known the cladding did not work as it was being marketed.
Hughes told Justice Whata the James Hardie group of companies was negligent in its actions.
"Your Honour, there was no testing of any kind whatever on Harditex prior to its launch in relation to weathertightness."
Red flags were raised early on, Hughes said, from the small amount of testing they did on cladding. Testing in 1989, Hughes said, showed Harditex suffered "degradation" under extreme weather conditions. The cladding was withdrawn from sale in 2005.
Hughes said James Hardie's lawyers could not find a single homeowner for this case who had the Harditex product on their home and had no issues.
"It would have been entirely open to James Hardie to, for example, put an advert in the paper... 'we'll give you $2000 if you've got a Harditex home built in the last 20-25 years, and you've never had a problem with it'," he said, to laughs from the plaintiffs sitting in court.
The Leighs, who were hoping for a just outcome, said it had been nine years of pain for them.
"Obviously it's not just us; there are thousands of others out there in the same situation and that's the sad part about it.
"All my husband and I want out of it is our home. We're not interested in a single cent more - we just want our home back."
The case in the High Court at Auckland before Justice Whata is set down for 15 weeks.
RNZ
