North Dublin pyrite case gets underway

Structural defects in up to 750 north Dublin homes were caused by “mundane” factors unrelated to the infill material used in their construction, the Commercial Court has heard.

Most of the cracks appearing in the houses have no structural significance, lawyers for the Lagan group of construction companies have claimed.

Hugh O’Neill SC, for the Lagan group, accused Menolly Homes, which built the houses, of “jumping to conclusions” about the cause of the problems in the houses and trying to pass on responsibility for the defects to his clients.

Mr O’Neill was making an opening statement in the case brought by Menolly and other companies owned by developer Seamus Ross against the Lagan group. Menolly claims defective infill supplied by the Lagan companies caused the problems and is seeking indemnity against up to €60 million in damage claims that householders are expected to bring.

Menolly’s case is that the cracking in houses was caused by the presence of pyrite in the infill, which came from a Lagan-owned quarry at Bay Lane in north Dublin.

This claim was rejected by Mr O’Neill, who said that Menolly had convinced itself that pyrite was the problem and had then dismissed other contributing factors, one by one.

“We know that the situation in the country where practically every second house with cracks is having this attributed to pyrite. A problem which for some reason we managed to live without for many years is now said to be the root cause of endless cracking.”

Just because someone had a headache and nausea didn’t mean he had a brain tumour, Mr O’Neill said, but this was the leap that plaintiffs has sought to make.

He claimed that Menolly had rushed to get the houses constructed and sold when the market was booming and said there were defects in the design and workmanship of some units.

Counsel said there was no doubt that pyrite, along with calcite and gypsum, were present in the infill supplied by Irish Asphalt Ltd from the Bay Lane quarry. However, these minerals were present in small amounts and the mere fact that they were present doesn’t mean that the heave as alleged by Menolly had occurred.

When pyrite and calcite reacts in the presence of water and oxygen, gypsum is formed. However, Mr O’Neill argued that even if pyrite and calcite were present and a reaction had occurred, the gypsum produced would not be enough to cause the heave alleged.

The problem of gypsum growing in fissures and laminations in houses was potentially more problematic and this had happened in Canada, he said. However, the type of rock used in the north Dublin houses was entirely different.

He said considerable force would be required to lift an entire house, but when this happened the gypsum crystals formed were different from crystals growing into a void. Crystals formed under pressure were stunted while free-growing crystals were perfectly formed.

Mr O’Neill said his clients had carried out a vast number of tests, none of which had produced any evidence of imperfectly-formed crystals. There was also no evidence that the alleged pyritic heave was continuing, as one would expect. Lagan’s testing since January 2008 had shown only marginal movement in the cracks, and this was due to changes in temperature. This “blows out of the water” the theory about pyritic heave being the cause of the water, he said.