Building products maker James Hardie Industries says it faces potential net costs of up to $US47.6 million ($A51.16 million) with a slew of leaky building cases and the New Zealand Ministry of Education's class suit hanging over its head.

The Sydney-based company has taken a provision of $US20.4m over New Zealand leaky buildings constructed between 1998 and 2004 and a provision of $US15.2m over the ministry’s $NZ1.5 billion class suit against cladding manufacturers, according to its second quarter financial statements. The company’s expense for the claims was $US300,000 and…