Government urged to take defective blocks research seriously

The Mica Action Group is demanding that newly published research that has found that the mineral pyrrhotite and not mica is the cause of the defective blocks crisis in the county be factored into the remediation solutions for affected homes.

The campaign group is writing to the Minister for Housing Daragh O’Brien, Government officials, Engineers Ireland and all Oireachtas members demanding that research published last week in the leading international journal Cement and Concrete Research “be taken seriously”.

Chair of the Mica Action Group Lisa Hone said the group is urging the Government not to “dismiss the research”, as it shows the current redress scheme is based not on a premise that has now been scientifically dismissed.

“That has fundamental implications on how you actually go forward,” she said. “This research has been internationally peer-reviewed. It has now been taken to a different level.”

The article was based on a study carried out by researchers at Empa in Switzerland, Ulster University, and the TA Group.

It states that the primary failure mechanism of the concrete blocks is caused by the oxidisation of the iron sulphide mineral pyrrhotite which is releasing high levels of sulphur.

The theory has been widely accepted by defective block campaigners in recent months.

Ms Hone said that while the research was presented to the Oireachtas housing committee last year, the publication of it in a peer-reviewed international journal means the approach from the Government to the remediation of homes must change.

“It has to be taken seriously by the Government, by engineers, by local representatives, in terms of the implications of this for the remediation of affected concrete homes.

“This is moving away from a hypothesis that says this is a freeze-thaw issue, which is triggered by high levels of mica. But if the primary mechanism of failure is the oxidation of the iron sulphide minerals - that puts a completely different perspective on it in terms of how you're going to remediate going forward.

“A, you have to make sure you are looking for the right thing and B, you have got to make sure you have remediation in place that is appropriate for the cause of the degradation.”

The new research means interior walls have to be examined and the impact on foundations has to be taken into consideration, she said.

“If it is the same supplier [that supplied the foundations and supplied defective blocks], then there is a very strong likelihood that you will have the same aggregate in the foundations.

“It is the only humane thing to do for the Government to actually take into account and consideration the testing of the foundations.

“There now has to be very clear lines of investigation in terms of IS 465 (the protocol for determining whether a building has been damaged by concrete blocks containing certain excessive amounts of deleterious materials) given that we know that internal sulphate seems to be the primary cause of the degradation of the bock. That’s what you need to be looking for.

“There has to be absolute clarity on what IS 465 is aiming to do.”