A homeowner says the leaky building scandal caused her neighbourhood to tear itself apart and unleashed stress worse than when she had cancer.
Another described a battle to fix a leaky house as nine months of hell.
They are among hundreds of homeowners who say Harditex monolithic cladding caused expensive, unhealthy problems including damp, mould and rot.
But the James Hardie group of companies denies claims in the $220 million class action, instead citing shoddy building practices and industry deregulation.
Lesley Wheatley told the High Court at Auckland she bought a home for her brother to rent in 2009, on the city's North Shore.
She said it seemed sensible because her brother needed a place to stay and she knew she could trust him.
"Never did I think that this property would cause so much heartache."
Four years after buying the unit, problems with the Oteha property emerged.
Wheatley said the unit was one of 14 and soon the whole complex needed recladding, costing about $300,000 each or $4 million in total.
She said she was the complex's body corporate chair, and the expense of recladding caused tensions in the group.
She said two homeowners unsuccessfully sued her, exacerbating the tension.
"I can honestly say that the impact that cancer has had on my life was incomparable to the stress this [caused]."
She said the unit was built in 1999 and when she'd first bought it, no possible issues with weathertightness were noticed or pointed out to her.
"The previous owner had been very diligent with maintaining the property."
Megan Barnes from Wellington told the High Court she bought her Hataitai house in 2011.
"The property ticked all the right boxes for me and I could see myself living there for the long term. It appeared to be low maintenance."
But three years later, she noticed cracks above the shower.
Barnes said she called a building inspector.
"He soon said I had bigger problems than a localised bathroom issue."
She called a thermographer who provided a "doom and gloom" assessment.
The thermographer found raised moisture levels throughout and obvious areas of rot, Barnes told the court.
"I was gobsmacked and devastated to receive this news. To me, this was an absolute disaster."
In September 2015, a full reclad commenced, taking nine months.
"I could not afford to move out during the reclad. I found the whole experience stressful and frankly hellish."
She said local council inspectors visited frequently. Some were reasonable, but one inspector demanded a whole wall be replaced.
Barnes said an $173,000 initial cost estimate ballooned to $250,000.
She funded recladding from savings and with help from family, and had to pay in instalments.
But Barnes said the builder was not good with finances, and started asking for money up front, so her architect had to get involved to help manage these payments.
Nearly six years on, she is still repaying her family and worries she will never be able to sell.
"It worries me what buyers might think," she said. "There is a stigma around leaky homes."
Lawyers for James Hardie have suggested some of the leaks homeowners described might have come from sources other than Harditex.
The company has also said if Harditex was installed in accordance with company guidelines, leaking wouldn't happen.
And James Hardie has argued it was getting sued, instead of builders or inspectors, because it was the only entity left with enough money worth pursuing.
The trial before Justice Christian Whata is expected to last until at least September.