The mineral muscovite mica has led to defects in building blocks used in at least 5,000 homes in the northwest, causing cracks to open up in many buildings. The Cabinet last year approved an enhanced scheme to cover repairs or rebuilding for affected homes.
A number of homeowners in Donegal have also been alerted to the presence of pyrrhotite in their blocks, on top of mica. Pyrrhotite is a naturally occurring iron sulfide which can react with oxygen and water and lead to cracking and swelling in concrete. As such, it has been implicated internationally in the deterioration of houses.
Now the national protocol concerning the remediation scheme for homeowners affected by mica and pyrite is to be reviewed amid concerns about the existence of other deleterious materials in the properties.
A review is under consideration regarding the national standard, known as IS 465, after opposition politicians and campaigners raised their concerns. The protocol is being used by engineers and geologists to assess damage in properties where concrete blocks are suspected to contain mica or pyrite.
Minister for Housing Darragh O’Brien has confirmed that an assessment will take place of the protocol underpinning the remediation scheme.
“Officials from my department have since met with the National Standards Authority of Ireland (NSAI) and other relevant stakeholders and I can confirm that a review of the standard will be carried out,” he said in response to questions from Sinn Féin TD Pádraig Mac Lochlainn and Independent TD Thomas Pringle.
“Meetings are ongoing between the relevant stakeholders to consider and finalise the scope of the review required, what further research is necessary, and the timescale for completion of the review.”