By Jack Caldwell - Mining Engineer - Robertson GeoConsultants

Someone recently asked me what I know about pyrite damaging houses. The question came from a young surveying student at a technical college in Ireland. Here is the story. Apparently 20,000 new houses in Ireland are cracked and damaged because a pyrite-rich rock from a local quarry was used in construction of the houses. The lawyers gather but nobody accepts responsibility because it is estimated that more than ten million Euros will be needed to rectify things, namely take out the pyrite-bearing rock and replace it. Here is one of many postings that provide more details. This link tells in part:

“Up to 20,000 homeowners are facing the devastating “pyrite problem” which is destroying recently built houses. The Irish Independenthas learned that this many claims for pyrite-related damage, such as cracked floors and walls, have been made to the builders’ insurance company HomeBond — which may not have enough funds to cover the cost of all the claims. According to an Irish Independent investigation, there are 20 building firms which have used material containing pyrite from at least four suspect quarries — which are located in Dublinand Meath. These quarries are still functioning. The affected houses are located in parts of Dublin, Meath, Kildare and Offaly where pyrite — a mineral that expands in the presence of moisture and oxygen — has been discovered in the infill material put in below their floors. In Kildare, one family bought a €560,000 home which has been damaged by the presence of pyrite. Yet they are being offered only a €38,000 settlement by HomeBond when the total repair bill could be up to €220,000.”

In the mid 1970s I was asked to go to a coal mine in Natal, South Africa. They had recently completed a new very large dining room for the miners. The floor had begun to lift soon after completion of construction. The floor slab was badly cracked by the time I got there. At first I suspected heaving clays, but there were no clays to be seen. The material beneath the cracked slab was compacted rockfill. It looked sound and solid.

Luckily I was accompanied by the late Adrian Smith, an excellent geochemist. We took samples of the rock, tested it, and sure enough the individual rock pieces swelled on wetting and heating. It was the pyrite or the equivalent thereof to blame. We advised them to remove the floor slab, remove the rockfill, and replace with inert materials not taken from the mine’s waste rock dumps. They did this. We wrote a paper which you can read at this link.

The lesson learnt from this story is that the lesson is never learnt. If you run a mine or a quarry, or use materials from mining or quarrying, be beware of the quality of the rock. It may look sound, but it is not necessarily so. It could be a swelling, heaving, expanding nightmare.

We pity those poor Irish home-owners. They willhave to live with cracked houses or spend a fortune taking out the pyrite rock and replacing it with good stuff. In most cases I would guess it will be cheaper to know down the house and start again.

Maybe a lawyer will help, but I doubt it. If you skimped on engineers in the first instance, lawyers in the second will only be a more expensive route. Here is the ad from Lavelle and Coleman if you still think a lawyer might help:

“We act for a large number of homeowners in DrynamHall, Beaupark and Myrtle, the Coast, in respect of defects caused by the mineral pyrite in their homes. For most homeowners, the presence of this mineral in the infill of their properties has manifested itself in the form of cracking and other defects throughout the house, both interiors and exteriors. We have engaged independent experts, namely geologists and engineers, to identify the practical problems that need to be addressed for homeowners and the remedial works that need to be undertaken in individual homes. If your home requires immediate works, you have to be certain that those repairs are adequate and properly done for future protection. This is necessary to maintain the value of your home. Our objective is to ensure that homeowners we represent achieve an outcome that fully protects their investment in their home and adequately compensates all of the losses they have or may suffer, without cost to homeowners. We are meeting clients throughout Ireland, and have been instructed in respect of defects in housing estates in Edenderry, Enfield, Kilmessan, Rush and Blanchardstown.”

Of course you could go to your local politician—as always they are in on the act, establishing committees and interest groups to get the taxpayer to pay. Here is a bit from one interesting report:

Mr Higgins welcomed the establishment by Minister for the Environment Phil Hogan of a panel to look at the pyrite crisis, but he was concerned the Minister had said the State was not a party to the issue or in any way liable for it, because it was a civil matter. “This is deeply worrying for affected homeowners” because the implication was that “they will be left with their homes coming apart at the seams while a gaggle of developers, builders and insurance companies slug it out for years in the courts to try and evade their responsibilities.” He called for pyrite-affected homeowners to have significant representation on the panel, for a remediation scheme and fund to be established and for the State to “go after whatever corporate entities are partially responsible for this”. Mr Higgins said the Taoiseach had a moral responsibility because the State overlooked this problem and the proper supervision of it. The State had a “serious responsibility” because it and the building regulator were negligent in not supervising the materials “going into these homes when it had known about pyrites for decades”.

I will never get to see those cracked houses, although I would love to, for I have undertaken many a project involving assessment of causes of cracking of houses. But I do not need to see the housesto know that the rock has to go, and no amount of lawyering or politicking will adequately solve the issue. Good luck to those poor home-owners.