Catherine McGinty, 20 Mar
The ‘register’ of properties affected by defective concrete products
and blocks established by Derry City and Strabane District Council
should not be restricted to the minerals, mica, pyrite and pyrrhotite,
according to a member of Donegal County Council.
Cllr Frank McBrearty, himself an affected homeowner, said it was vital
Derry City and Strabane District Council’s definition be widened to
include “all deleterious materials and all reactive sulphide minerals”.
What Council described as its ‘data collection exercise’ followed a
home here being described as the first in the North with a confirmed
case of ‘mica’, in November 2022.
The home belonged to Danny and Kate Rafferty, from Beragh Hill Road in
the Skeoge area of the city, who carried out testing on their blocks
when telltale ‘spider cracks’ appeared on the outer wall and chimney of
their house.
[House_affected_by_Defective_Concrete_blocks_%281%29_Cropped-1668079152
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The term 'mica crisis' is a complete misnomer
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Speaking to Derry Now, Cllr McBrearty said: “As a result of two years
of investigation, undertaken by Derry’s Dr Ambrose McCloskey, chartered
engineer and IS465 registered engineer; and Kieran Coyle, chartered
structural engineer; and international experts, Professor Paul Dunlop
and Dr Andreas Leemann; other experts from Canada, US and Norway; and
myself, I believe, Derry City and Strabane District Council must now
look at an investigation into all deleterious materials and reactive
iron sulphide minerals, which could possibly be present in properties
in the North of Ireland, constructed with concrete products bought from
Donegal.”
“The people of Derry and Tyrone should not be hoodwinked into believing
this is a ‘mica’ issue.
“The words, ‘all deleterious materials and all reactive sulphide
minerals’ must be included and a full, transparent investigation
conducted by professionals like Professor Paul Dunlop, Ambrose
McCloskey, Kieran Coyle, the engineer acting for our family, and
others, if necessary.
“We do not know how bad the situation is in the North because there is
no oversight or policing of the industry in Donegal. This is going to
manifest over time and affected properties will become uninhabitable,”
said Cllr McBrearty.
Cllr McBrearty's research document can be read HERE.
Cllr McBrearty’s warning came as Ulster University academic, Professor
Paul Dunlop, and four colleagues published their newly peer-reviewed
paper, "The ‘mica crisis’ in Donegal, Ireland - a case of internal
sulfate attack?”
The paper confirmed that geological mineral mica was not the primary
cause of failure of defective concrete blocks in Donegal homes, rather
it was the mineral pyrrhotite present in the aggregate found in
defective blocks in the county.
Co-authored by Dr Andreas Leemann; Professor Barbara Lothenbach; Dr
Beat Münch of Empa’s Laboratory for Concrete and Asphalt, Switzerland;
Thomas Campbell, TA Group, Ireland and Professor Dunlop, School of
Geography and Environmental Sciences, Ulster University, the paper was
published in ‘Cement and Concrete Research’.
According to Professor Dunlop this is the number one ranked journal
internationally for Building and Construction.
Speaking to Derry Now, Professor Dunlop said: “Our research is the
first internationally peer reviewed article that provides clear
scientific evidence that defective concrete blocks in Donegal are
failing as a result of internal sulfate attack directly connected to
the presence of highly unstable pyrrhotite and not the mica freeze-thaw
process as was proposed by a government report published in 2017 and
incorporated into the National Standards Authority of Ireland (NSAI)
testing and remediation standard IS465.
“This new scientific evidence is important for the government officials
and policy makers who are dealing with the defective concrete block
crisis to ensure science based solutions are at the heart of government
solutions for affected homeowners.
“Its publication is also timely for the NSAI which has been calling for
rigorous, independently peer reviewed scientific data for its ongoing
review of IS465.
“In addition, it provides information for the National Building Control
and Market Surveillance Office which is tasked with market surveillance
about the obvious risks for concrete failure when aggregates containing
pyrrhotite are used and reinforces the need for robust surveillance of
the extraction industry and concrete manufacturers,” said Professor
Dunlop.
Derry City and Strabane District Council has subsequently issued a
public call out to property owners in the area, who have evidence that
their residence / dwelling has been impacted by mica, as certified by
an authorised mica testing organisation, to get in contact with it so
it can add their details to the database.
Council stressed the purpose of this exercise was to collate data only
as it could not carry out any form of ‘mica’ testing.
It said: “This data collection exercise will allow Council to quantify
how many homes / properties within the Derry and Strabane District have
already been tested and deemed to be affected by mica.
“Property owners are urged to get in touch by sending their name,
details of the affected property and contact number, along with a copy
of certified testing / documented evidence to prove your property has
been impacted by mica to the following bespoke email address:
mica@derrystrabane.com.
“The information will be collated and presented to a further meeting of
the Council’s Environment and Regeneration Committee for elected
members to review and consider going forward.”