A multimillion-dollar class action has been filed by building and homeowners over leaky building products supplied by Carter Holt Harvey.

Fed-up property owners are seeking at least $40 million in damages after their properties were constructed with Shadowclad.

Already subject to court proceedings, the Ministry of Education alleges the product was defective and left the ministry with about 800 leaky school buildings.

The estimated repair bill for the leaky school buildings the Ministry of Education is seeking has been reported as in excess of $1.1 billion.


The class action was filed at the Auckland High Court on Monday on behalf of owners expressing concern over "weather-tightness" issues with Shadowclad.

"In 2014 the Fair Go television programme found 24 property owners who believed they had been supplied faulty or sub-standard Shadowclad material.

"Given Fair Go's research, the extent of the Ministry of Education's claim, and the
approaches we have had, clearly the issue is significant.

"This has led to the funded class action," Adina Thorn of Adina Thorn Lawyers said.

She said 117 owners from around the country joined forces and will not face out of pocket expenses while the litigation funding is in place.

Although the claim is set for at least $40 million, Thorn said it is likely to round up to around $50 million in the wake of recent developments.

Thorn also added that they will still accept further claimants but they will have to get in quick to be apart of an action without having to meet any high legal, court and technical costs.