The Irish Government could have avoided Donegal’s crumbling homes crisis if it had followed European Standards on pyrrhotite set out in a directive 23 years ago, a world-leading concrete expert told a local conference today.
Homeowners, campaigners, politicians, academics and international experts gathered at An Grianan Hotel in Burt for the 2025 Defective Concrete Conference.
The conference was organised and hosted by Ulster University and academics Dr Eileen Doherty and Professor Paul Dunlop whose recently published research debunked the theory that crumbling homes have been caused by the Mica mineral.
Dr Andeas Leaman, Senior Scientist Group Lead EMPA Swiss Federal Laboratories for Materials Science and Technology, showed the 200 attendees at the conference a dam and a bridge – high up in the Swiss Alps – built with Mica concrete to show that Mica was “never” the issue in defective concrete.
Dr Leaman told the conference that when Buncrana-based Professor Dunlop first contacted him in 2021 and told him about the “Mica Crisis” in Donegal, his initial response was: “That sounds fishy to me”.
He said his initial scepticism about Mica being responsible for thousands of crumbling homes was confirmed three months later when he studied samples taken from affected homes in Donegal.
“I concluded in December 2021 that this was not a Mica crisis at all but a pyrrhotite crisis,” said Dr Leaman.
The academic said Mica does not damage concrete. He said there is an abundance of Mica in Switzerland including in an Alpine bridge and the Verzasca Dam (Contra Dam) in Ticino, famous for the iconic bungee jump scene in the film James Bond movie ‘GoldenEye’
“Mica isn’t a problem,” said Dr Leaman.
“The issue is pyrrhotite and internal sulphate attack. The EU set a standard in 2002 with a limit of 0.1 per cent maximum of pyrrhotite but nobody in the Irish Government cared. If this standard had been followed the crisis could have been avoided.
“The most sophisticated testing available worldwide and identified pyrrhotite oxidation and internal sulphate attack (ISA) as the cause of the crisis.”
Professor Dunlop said that working with research partners in Switzerland, the USA and Canada, they had debunked the Mica freeze-thaw theory.
He also pointed out that the Government’s 2017 report which identified Mica as the cause of the crisis in Donegal was prevented by the terms of reference from carrying out actual tests on concrete.
The latest award-winning research by Dr Leaman, Professor Dunlop and others has been included in the National Standards Authority of Ireland (NSAI) current public consultation on the IS465 standard.
This was presented at the conference which showed varying levels of internal sulphate attack on different areas of a home, with the other leaf being the worst.
And whilst the internal walls were relatively unaffected, these sit on rising walls which are affected. Further study is needed on the possible consequences for foundations, the researchers said.
The conference also heard that specialist testing overseen by Pierre-Luc Fecteau, Research Associate, Laval University, Quebec, Canada, has been ongoing at the home of MAG campaigner Lisa Hone outside Letterkenny. The testing is similar to those carried out in Trois-Rivieres city in Quebec.
Early results once again prove that the Mica freeze-thaw theory is not responsible for the defective homes, said Mr Fecteau.
“There is no freeze-thaw Mica in Quebec so it certainly doesn’t make sense that it could happen here in Donegal where mean average temperatures are much higher,” he said.
Professor Dunlop expressed frustration that the IS465 review continues to include Mica as a possible cause of the crumbling homes, with Dr Leaman describing its inclusion as “just wrong”.
