Key Post Pyrite in Foundations leading to cracks

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Re: Pyrite

Seriously Geld, that is just a disgrace and makes my blood boil!! I dont know what we are going to do. Waiting to see what our solicitors advises. Is just such a mess and unfair that we are the ones left now to deal wit it once the builders have made their money!
 
Re: Pyrite

Thanks SSB we too are awaiting to get sample done(costing 2k!) as in order to prove a case of damaging infill we need proof. As soon as we get this we are going to discuss futher with solicitor and no doubt it will be the builders(who are not owning up to anything at the moment) that will be liable. Only worries is the builders having a poor bank balance..surely then the government should compensate ?? Time will tell...

P.s. Geld must be very hard in your situation with a child but hopefully things will work out soon, at least builders are taking responsibility for the problem.
 
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I was told there was article in Times this week and that a court case had started ?
 
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I seen this too. The developers are taking the quarry company to court. Going to try and sue and get quarry to admit liabilty. So if they are sueing quarry surely we can sue builders??
 
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Hmmm.I think that even if the quarry lose their case they could appeal. IMHO a lot is riding on this outcome which in turn could affect all of us. Menolly didn't build our house but we are watching with interest.
 
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Geld, did the buildes come back and fix your property?
 
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did anyone hear about pyrite on RTE 1 last thursday ? It was supposed to be featured onthe programme about lunchtime ??
 
Re: Pyrite

did anyone hear about pyrite on RTE 1 last thursday ? It was supposed to be featured onthe programme about lunchtime ??

Yes I heard it discussed on the radio. The discussion dealt with a case of just 2 houses built by a small developer. The house owners had been told by homebond that there was a ceiling of 200k on what they would cover and these people were told that the only solution would be to knock their houses and rebuild. The cracks had got so bad they were unable to live in some rooms, I think one had even moved out altogether.

They said they have little chance of compensation as the small developer wouldn't have the funds now.

Can't remember any other details, or even what programme it was on.
 
Re: Pyrite

cheers pebbledash...did the discussion mention if any homes were semi-detached ? if houses affected are semi-d and have to be knocked down, surely the attached house
would be too ??!! How has it been done so far in other estates ?
 
I am an engineer, acting as an expert for many house owners around the country with Pyrite problems. This problem is widespread and is not restricted to Dublin Only. In fact this problem is present as far as Edenderry, Summerhill, and up to 50 miles from Dublin. To date we have identified 5 quarries in this greater area, that potentially supplied such contaminated material. If you need advice, contact me.
 
I have no experience of pyrite contamination and what follows may be if little direct relevant to the debate.
Also I'm an architect, not an engineer - I call on engineers for advice even on single storey extensions, never mind houses or apartments.
That means I 'm not an expert on structures, but it also means I am competent to comment on all matters in relation to buildings - I also ask good questions. ;-)

One thing is bothering me about all of these instances of foundations and walls cracking.
I accept that there may be pyrite contamination in the hardcore/fill/aggregate, but has anyone got a handle on how bad it needs to be to cause this level of damage to the building fabric?
Citing pyrite as the sole source of cracking and settlement in spec-built houses and apartments may in fact be correct in one or even all these cases, but I have come across cracking and settlement for other reasons.

In my experience:

  • inadequate design
  • poor detailing and
  • poor workmanship
are the usual causes of settlement and cracking.

Design and Detailing:

The work of the designers begins at site assessment stage, with the selection of where to build the buildings and we have seen heated debates in the recent past about building on flood plains north of Dublin City.
Ground conditions can cause significant problems for substructures, and their design must address adequately any issues arising from groundwater, contaminants already in the soil or geological features.
Some parts of Dublin have underground watercourses and/or underground hollows and building on or near them can involve piling the foundations with ground beams between the piles.
This can be expensive, not just for the foundation work where costs can be offset against the labour of digging and preparing trench foundations, but also for ground floor slabs.
Poor ground may have to be excavated and backfilled and this filled material, even if properly selected, placed layered and compacted will be liable to settlement.
If the depth of fill exceeds 1.2M or so, the engineer is likely to recommend the use of precast slabs for the ground floor of the lowest apartment.
This has cost implications in terms of detailing for radon gas and services penetrations and pipe connections.

Materials and Workmanship:

The following non-exhaustive list of activities all have to be done to specified standards or else cracking may occur:

  • selection of the aggregate
  • selection of the cement
  • selection of admixtures
  • water quality
  • mixing of the concrete
  • the water ratio
  • time to placement
  • distance to placement
  • the placement and vibration
  • allowing curing before imposing loads
  • temperature of the works while they cure
The correct production and placement is only part of it and the aggregate is only part of that.
In other words, while contaminated aggregate can cause problems in itself, there are many other sources of cracking.
If the ground is too poor for strip footings, special foundations will be needed to transmit the load of the superstructure to a bearing stratum.
Before you get anywhere near the site with a digger, the engineer and architect have to assess and agree the structural system and detail the building accordingly.

Preparation

Before you get anywhere near placing concrete, even with a straightforward house foundation, the excavation and preparation of the ground has to be carried out, which inter alia includes;

  • the identification, excavation and filling in of soft spots
  • the laying of graded hardcore in layers depths to engineers spec
  • the compacting of the hardcore
  • the blinding of the hardcore with sand or lean mix
  • the blinding of the foundation trenches with lean mix
  • the placement of reinforcement to allow correct cover
  • the reinforcement of the base of the foundation
The Pour

After that you need to carefully commence the work:

  • the pouring of the concrete itself
  • distance from source if pumped
  • height from outlet to poured level
  • vibration of the concrete to eliminate air pockets
  • aeration of the concrete to help protect the steel
  • adequate curing time to develop strength.
  • use of concrete of the correct strength
  • keeping it at the right temperature while curing
The temptation on large sites can be to pump to the maximum distance and/or drop concrete from too high a level.
These should be resisted because they can disrupt to the mix matrix [sand/cement/aggregate/water] and/or cause cavities forming within the setting concrete.
As you can see all of this can be very complex work and the rate at which work can proceed on site is determined to a degree by the minimum time taken to build in concrete - if adequate time isn't allowed, the work will suffer.

Bigger Building Work:

On a medium-to-high-rise apartment block, more sever construction issues can arise.
The extra loads from the higher structures [including wind loads] may mean that reinforced foundations or piles are required regardless of the ground conditions.
On large building sites the scale and complexity of the project can involve several different pours [piles, ground beams, slabs] proceeding simultaneously in separate areas of the site.
Bigger building projects inter alia requires significant additional supervisory work by the contractor as well as specialist knowledge and skills over and above those of the small house builder.

Investigative Work

Establishing whether or not pyrite is present is relatively affordable and can point to one possible cause of cracking and settlement, if discovered.

However if the providers of foundations to the affected properties did not carry out the work compliantly, cracking and settlement may occur for reasons totally unrelated to presence of pyrite in the mix.

Assessing all the other factors could be a long and expensive process and not one to be undertaken lightly by a house or apartment owner.
Where an apartment block is affected, or where significant numbers of houses in an estate are affected, the owners should consider pooling their resources to fund a professional investigation team.

To help form an opinion in relation to this matter the following matters should be assessed:

  • the level of investigative work undertaken by the designers prior to site
  • the detail design of specialist foundations to support the superstructure
  • the level and quality of testing or concrete cubes and materials
  • the level of on site check-in and testing of materials supplied separately
  • the existence of warranties or undertakings from suppliers of materials
  • the level of contractor's personnel involved with supervising the concrete work
  • the retention of a competent site engineer by the developer, contractor or engineering firm

Local excavations may be required to be carried out on:

  • an absolute basis involving extensive excavations or
  • a statistical basis where only a few key corners of buildings are exposed in a large scheme
These will allow professionals to visually inspect and assess empirically [through testing or coring] whether or not the foundations were properly sized, placed and constructed.

Conclusion and Caveat

Inadequate design, site preparation, site supervision, poor detailing, materials and/or workmanship are possible causes or contributory causes to cracking and settlement in buildings.
It may be helpful if all of these other issues are explored by professionals acting for the injured party where pyrite is suspected of being the prime cause of the problems,
This post is not exhaustive and the comments herein are justified and are made as fair comment in the public interest based on known issues in the building industry.
This post is not intended to raise unnecessary concerns amongst persons already worried about their future and the future of what they thought was their lifetime investment, their home.
This post shows some avenues of investigation and redress that any competent solicitor or building professional should consider when assessing any instance of cracking or subsidence in a building.
 
wow, that is a long reply. Well thought out. The entire process of the effect of pyrite in infill below floor slabs is very complex and involves:
  • Presence of pyrite in sufficient concentrations,
  • External environmental conditions such as humidity, heat, oxygen
  • pyritic conversion of framboidal pyrite to gypsum and other byproducts
  • expanion of the aggregate to such an extent that the floor slab rises and potentially the rising walls below DPC level being pushed out in a lateral manner
  • rising of some of the internal walls either stud partition of blockwork
  • Internal cracking of floor slabs and internal walls.
To date we have in place the following protocols:
  1. Initial engineering investigation procedures and report requirements
  2. if pyritic conversion is suspected, a crack monitoring protocol can be implemented
  3. If the cracking is so severe, then teh above is bypassed and a Sampling and Testing Protocol is then implemented.
  4. From the results of all the above, we then can form a definite opinion as to what is going on.
Naturally, other side issues such as foundation & house construction comes into play. We are working with an English Testing facility along with an English Geochemist expert in confirming the complicated processes that take place.
One word of caution to all houseowners: To date we have identified five contaminated quarries, andthe problem is huge. Potentially theer are thousands of houses affected, with the bill running into hujndreds of millions for the repairs. Accordingly speed is of the essesence.
 
there is a big case in North Dublin where all the houses in the estate are suing the builder who is currently attempting to fix the issues. Very expensive to do. Involves moving out - paid for by the builder - form may months. Very slow process as it involves laywers.
It was in the papers a few months ago.
 
wow, that is a long reply. Well thought out.
<snip excellent summary post>.

<bows>

Possibly it was too long, so I'm trying to shorten my replies:
Many thanks for confirming the position and outlining the processes.
This is something I'll need to take into account when I do building inspections.
My inspections are limited to visual inspection only save where opening up is specifically called up.
However, I don't think clients will think I'm giving a great service if I fail to mention the issue in my report and suggest some simple and cost effective method that could allow my clients establish the position.
I'm thinking here about a report on a house that might be showing no signs of problems at the moment.
I have four questions and if you could consider them I'd be very grateful:

#1: Is there a cost effective investigative method that can be used and what does this entail?
I would welcome advising them to involve an engineer at the building condition report stage - this is about giving a service and covering my practice legally, not about me trying to "hog the glory", per se.

#2: Are there any points you could offer to help determine the likely risk of being affected by pyrite?
For example, what information can be released at this point of the investigation re:

  • names of affected builders
  • names of affected developments
  • names of quarries or suppliers that are known sources of pyrite
#3: Are the government doing anything about it?
I think heard a report that sounded like Minister Gormley saying its a civil matter to be settled between the parties, but I may be corrected on this.

#4. Your report mentions humidity - does this imply that moisture or water may play a part in activating the pyritic reaction?
Could a change in groundwater conditions - e.g.

  • locally rising levels due to porous pavements in an area that previously may have had trees transpiring water out of the ground, or
  • flooding, in an extreme case
cause problems in houses that may have had no problems previously?

Thanks in advance if you get a chance to reply and thanks anyway for your information to date.

onq
 
The cost is twofold:
1. A full engineering assessment including visual condition survey, floor level survey, and possibly installing monitoring pins and telltales, approx €2300 + vat
2. A geotechnical examination which involves the removal of some infill and testing €2400 +vat

#2 at this stage, what is in the public domain, I could discuss. The rest is subject to civil court action. I know a lot of the developments around greater dublin that are affected. Some are more so than others.
#3 Not an issue for the government. It is covered by defective materials under the Building control regulations. Civil case issue or Structural Guarantee.
#4 Moisture, specifically humidity is one of the ingredients for the reaction. Variable water tables is an issue. However, there are many others and they all have to combine to bring about the pyrite chemical reactions that causes gypsum, which causes the expansion.
 
good info pyyriteengine, thanks. I know there was a letter issued to builders last year informing them from then on, that they are to ensure that infill has to conform to certain conditions that would help alleviate any issues such as this. Our lawyer told us the same thing as you - that the problem is indeed huge with nothing being done until the court case has been resolved...
 
Hello,
it was very informative to read all your comments... We live in a development affected by pyrite, but as we own a top floor apartment in the building we were initially told by the developer that we were not impacted, however the people in the 2-story townhouse underneath us has had their ground floor tested and they have found pyrite in their infill.
Recently we have asked for a written statement from the developer that certifies we have no pyrite, but it took them 2 months to basically get back stating they cannot provide such certificate until the owners of the house underneath us will allow them to carry out remedial works.
Our solicitor suggested we get an engineer to establish whether we are affected or not, but since we don't have any visible cracks neither inside nor outside, we don't think there is any point. Also the response from the developer seems to indicate we are affected indirectly.
Does anyone think we should follow the solicitor's recommendation and request an inspection anyway,(costs seem to be rather high though) or should we wait for visible signs... we feel like we are sitting on a time bomb!
 
I would not recommend any inspection by a Structural Engineer at this stage. If you have no symptoms of the problem, then most likely you will not be affected. In particular, if you have a concrete floor between you and the ground floor apartment, you are reasonably safe. Dont panic yet. Only if you see problems arising in your apartment, should you consider the inspection. The cost of one would be approx. €1450+vat, so be careful. I have seen many apartments over ground floor ones, that have had no effects yet.
 
Re: Pyrite

We also just got our report back and it is confirmed 3-4% pyrite so we are taking legal action as the builders have still NOT taking liability. It is crazy they are only digging themselves a bigger hole to get out of...fingers crossed we win this and I have a feeling we will.
 
Re: Pyrite


3-4% of pyrite would seem like a very small concentration of what is essentially a naturally occuring substance... for example thats 400 kilograms of pyrite in 10 tonnes of filling...!!

have you gotten legal advice on this....

i would be very very surprised if that small concentration of pyrite can account for structural defects in a new build...
 
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