UP TO 500 people may have to move out of their newly built homes in Ballymun in north Dublin because of damage caused by the defective building material pyrite.
The presence of pyrite is suspected in up to 140 houses and apartments in two new estates built to rehouse residents of the former 1960s high-rise flat complex.
Preliminary tests carried out on stone samples in the houses in Owensilla and part of the Carton estate came back 50 per cent positive for pyrite – a sufficient level for 140 occupied homes to need a full assessment.
Pyrite remediation work costing €10 million is already under way in 122 houses in another part of Ballymun. However the defective building material in the Sillogue estate was found before any tenants moved in.
Managing director of Ballymun Regeneration Ltd (BRL) Philip Maguire said it would not be possible to estimate the cost of fixing the pyrite problems in Carton and Owensilla until investigations revealed the extent of damage to each house.
However he said the fact that the homes were occupied meant it was potentially a more difficult, disruptive project than the Sillogue works.
“These two schemes are even more complicated because there are people living in them. There’ll be a whole battery of tests on each house, and where they come back positive we’ll have to make plans to rehouse the tenants. We hope that a good few will come back negative. We’d like them to all come back negative . . . In Sillogue they were all positive.”
The final test results should be back within six months.
Pyrite, sometimes known as fool’s gold, occurs naturally in stone. When exposed to air or water it becomes unstable and can cause structural damage, including cracking and buckling of walls and floors. Replacing it with sound material is very costly.
“Depending on the type of house and the construction method it can cost €50,000-€60,000 a pop to fix,” said Mr Maguire. He expects to have the work to 60 of the Sillogue houses finished by Christmas and the rest by next Easter, but the problem will have delayed the delivery of these houses by three to four years.
The work is being funded mostly through a loan from the Government. BRL and the contractor have served legal proceedings against quarry owners Irish Asphalt/Lagan and anticipated the loan would be repaid if the action is successful.
The pyrite loan was entirely separate to the exchequer funding for Ballymun’s regeneration and would not affect that project, Mr Maguire said.