In response to political lobbying the Government established an Expert panel in 2016 to investigate the reason why building blocks in houses in both Donegal and Mayo were crumbling into Weetabix type material.
The report was concluded and presented to the Minister for Housing in June 2017.
From reading this report a number of salient points emerge that gives rise to justifiable concerns . . .
The report was concluded and presented to the Minister for Housing in June 2017.
From reading this report a number of salient points emerge that gives rise to justifiable concerns . . .
- Why did the terms of reference, as set out by the Government, not allow the Expert Panel to send off for analysis the crumbled material from the blocks, which was readily available, to determine scientifically what exactly caused the building blocks in the houses to degrade into virtual dust?
- Why did the Expert Panel members take a guess, devoid of all scientific proof and against all engineering principles, and pin the cause of the crumbling effect on a material called Mica while all the time deliberately ignoring the more serious suspects i.e. reactive Iron Sulphide Minerals and other deleterious materials, the effects of which as highly qualified civil engineers and geologists they would have been very much aware of and listed as a problem in concrete manufacturing in Ireland as far back as 1954?
In this excerpt from the Expert Panel report (page 39) it becomes clear that the members have decided, devoid of any scientific analysis, that the cause of the problem in Donegal is indeed Mica while completely ignoring the possibility of the more deadly Sulphide minerals:
The Panel concludes that the nature of the problem is manifested primarily by the disintegration of the concrete blocks used in the construction of the affected dwellings in Counties Donegal and Mayo which in turn results in a pattern of cracking in the external render of these dwellings. The affected dwellings are single storey, dormer and two storeys in estates and one-off rural types and were constructed by contract and by self-build. Based on information received, the Panel is of the opinion that the reason for the widespread pattern cracking in private dwellings in Counties Donegal and Mayo is primarily due to the excessive amount of deleterious materials in the aggregate used to manufacture the concrete blocks.
The deleterious material in County Donegal was primarily muscovite mica. While in County Mayo it was primarily reactive pyrite.
The problem was exacerbated by the severe exposure of many of these dwellings and the ingress of moisture into the concrete blocks which was possibly accelerated by the extreme weather conditions in winter 2009 / 2010 and late winter 2010.
In County Donegal the ingress of moisture into the concrete blocks, aided by the presence of more than normal amounts of muscovite mica, and the subsequent freeze thaw action which the concrete blocks were unable to withstand is likely to have led to the disintegration of the concrete blocks and the pattern of the associated render cracking.
The question must surely be asked why did they do this?
Were they simply following the route that had been laid out in front of them in the Govt terms of reference which did not allow for scientific analysis thus preventing the real cause of the problem from being identified?
Steering clear of the Iron Sulphides (no analysis of the crumbled building blocks) which if found to be the real cause of the problem would have meant complete and very expensive demolition and rebuild of all infected houses across the board as against a cheap, partial outer wall replacement if they could instead blame it on Mica?
This line of reasoning points to a well organised plan by the Government in the first instance by insisting on a desk top study only which they knew would knowingly identify the wrong material Mica as being the cause of the problem and thereby and all importantly limit the financial exposure to the state's exchequer.
This was truly a shameful plan where we see the state and numerous of its institutions and committee's come together in a premeditated and well organised synchronised way to knowingly propose a worthless solution to innocent homeowners' problems in order to protect the state's coffers.
The following excerpt explains the dangers of the ignored reactive sulphide minerals and other deleterious materials that were known to be a problem in the manufacture of concrete products in Ireland since 1954 ...
2.2.5 Deleterious materials
Deleterious materials, chemicals and characteristics related to aggregate type and sources have an effect on concrete strength and durability. Reference should be made to the harmonised European product standards (commonly referred to as hENs) for the assessment of aggregates and the associated Standard Recommendations and relevant Codes of Practice which provide national guidance for their use in construction products and works in Ireland. The following not exhaustive list describes the most common deleterious materials and their effect on concrete, which include:
2.2.5.1 Sulfates Interaction between sulfate and cement paste causes the generation of the mineral ettringite through the interaction of tricalcium aluminate and gypsum. This causes extensive cracking, expansion, loss of bond integrity between the cement paste / aggregate particles and the alteration of the cement paste composition. In wet / saturated, low temperature conditions (<15oC) a carbonate / sulfate interaction known as thaumasite attack occurs. Thaumasite replaces the cement paste causing the concrete surface to soften and eventually disintegrate;
2.2.5.2 Sulfides Sulfide minerals, in particular iron sulfides such as pyrite and the much more reactive marcasite or pyrrhotite, can have a considerable effect upon concrete strength. In-situ oxidation, disintegration and dissolution of iron sulfides weakens the aggregate strength. The chemical reaction between oxidising pyrite and calcite causes the formation of secondary gypsum with an associated volume increase (greater than twice the volume of the original iron sulfide mineral). In addition, the oxidation of iron sulfide's can produce sulfuric acid, which attacks the cement paste (i.e. Mundic Decay),
With this knowledge in their possession the expert panel members came to Donegal where they had numerous meetings with political representatives, members of the Mica Action Group and visit the sites of several badly affected crumbling block homes.
Horrendous stories of everyday living are related to them by families on the effects of watching and in fact listening to their houses progressively crumbling around them on a daily basis.
They viewed at first hand the scandal of the 'crumbling homes' that is evolving across Donegal. They even get to crumble the blocks in their own hands.
The most important point that was missed by the families and the campaigning groups was an understanding of the real agenda that lies hidden in the minds of the Govt representatives that would only become clear when the relevant legislation was assembled.
They are employees of the state whose primary function is to protect it at all costs and minimise any claim that is made against it.
They come among the people giving the friendly impression that they too only want a fair and just outcome for what has befallen the affected homeowners.
In fact, nothing could be further from the truth as we will see.
This Expert Panel report is now passed on to the next level of the Govt investigation which is the NSAI (National Standards Authority of Ireland) who decided to set up a Technical Committee that would be asked to design an Irish Standard that could be applied to 'fix' the crumbling Donegal homes and based on Mica only.
Important to remember that the Expert Panel makes it clear in their report that it was not part of their remit to send off the crumbled material for scientific analysis and even though they point the finger at Mica as being the cause of the problem they nevertheless state that further scientific analysis is required.
It is completely revealing that the proposal by the Expert Panel for further research will now be restricted by the NSAI Technical committee to researching the effect of Mica only in a freeze/thaw situation.
To this end Donegal Co Cl supplied seventy samples from four affected social housing stock for analysis by Fastnet Analytical.
Everyone involved now concentrates on building a plausible picture in an effort to blame Mica as the sole culprit for the defective blocks scandal in Donegal.
Reactive Iron Sulphide Minerals become the Elephant in the room and are completely ignored.
Questions must be asked as to why this was happening.
- Why did the Govt issue restrictive Terms of Reference which did not allow the crumbled block material to be scientifically analysed?
- Why did the Expert Panel go against all engineering principles and without proper scientific evidence put the blame on Mica on the basis of a guess?
- Why did the NSAI accept this incomplete report from the Expert Panel and not comment on the exclusion of the reactive sulphides as a possible cause?
- Why did the Technical Committee run with Mica and not insist on proper scientific analysis of the affected blocks?
There is a very visible thread running through this whole process which is to put the blame squarely on Mica and to ignore completely the very strong possibility that Reactive Iron Sulphide Minerals might well indeed be the cause of the problem.
A pattern has emerged of all involved singing off the same hymn sheet and falsely promoting Mica as the culprit material causing the blocks in Donegal houses to crumble.
The possible reason for this will be analysed in Part V.
Protocol I.S. 465 was now completed by the technical committee and presented to the Government by the NSAI in 2018 without challenge or comment by anyone and became the cornerstone of the upcoming 90/10 scheme which was passed into law as S.I. 25 of 2020.
The 90/10 scheme ( first scheme ) opens for applications from affected homeowners suffering from crumbling building blocks syndrome in June of 2020 and very quickly runs into trouble.
Almost immediately serious revelations appear when test results of the block cores from the affected houses start coming in from the testing laboratory Petrolab in Cornwall in the Autumn of 2020. These results are analysed and will prove beyond all argument or doubt that the real reason for the blocks deterioration resides with the Reactive Iron Sulphides and not Mica.
This and the reasons for the false promotion of Mica will be explained in Part V.
⏩ Enda Craig is a Donegal resident and community activist.
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