Pyrite and housing via the M3 motorway

In case you missed it. Top regional story in The Irish Times…

The M3 motorway which cost an estimated €1 billion will be officially opened today.

The 61km motorway linking the Dublin/Meath border with the Meath/Cavan border is believed to be the largest single road project to be constructed in Ireland and incorporates bypasses of Dunshaughlin, Navan and Kells.

In addition to the motorway itself, the overall project involves a network of 49km of ancillary public roads and 34km of farm access roads.

And a separate smaller story down the page

THE CHIEF executive of the National Roads Authority has written to a TD to inform him that pyrite was used in the construction of the M3 motorway in Co Meath.

In his letter to Fine Gael TD Shane McEntee, roads authority chief executive Fred Barry said that “as far as we are aware,” the pyrite was used as filling for embankments.

And the last line of an RTE report on an April 6 meeting of the Oireachtas Committee on Transport

Mr McEntee had asked the National Roads Authority if pyrite had been used in the construction of the M3 motorway and was told there was no evidence that it had.

A more complete Irish Times report on the same meeting

Mr Barry told Meath TD Shane McEntee there was no need for an independent audit of the M3 or the section of N3 from the West-link toll to Clonee.

Speaking at the Oireachtas Committee on Transport today Mr Barry said infill material for support structures such as cement pillars and steel bars was rigorously monitored and could be traced. The NRA was happy no material from the two quarries identified had been used in connection with either steel or cement.

He said the material from the quarries could only have been used in relation to embankments. In this regard, pyrite – if it had been present at all – was not boxed in by foundations as it would be in a house. There would be minimal impact if the material “shifted, heaved, or expanded” as it might in foundations.

And finally, a quote from the letter which was received by Deputy McEntee from the head of the NRA this week…

“In so far as we are aware the use of pyrite-bearing rock for the construction of the M3 was primarily as embankment fill, with some use as roads base”.

“As far as we’re aware…” qualifying statements are often dangerous.

In reality, however – though Deputy McEntee’s enquiries are welcome – the likelihood of pyrite causing serious damage to a road is fairly small. Pyrite expands when it comes in contact with water, in the enclosed foundations of a dwelling structure that’s a serious issue, in the open base of a road there is space for it to expand, hence the ‘no-biggy’ reaction. Still, while this news story gets a ‘meh’ it does give me a tangetal jump-off point to address another point. Sorry for the delay in getting it to!

Pyrite in gaffs.

Serious problem, which goes beyond one or two developers. The expanding mineral in the foundations can leave massive cracks in the walls of apartment blocks and housing developments. I ain’t talking hair-line either, I’m talking visible-from-a-distance type stuff. There’s one development along the Dart line where they’ve had to close the adjacent playground because the crack along the ground means it’s too dangerous for kids to play.

A friend of mine works for a company which repairs buildings which have been effected by pyrite. He showed me photos of one block he was working on where the walls had bowed outward by about 25 degrees… crazy-looking. I’ll try to get them from him to post here later so you can have a goo. They had to knock down all the internal non-structural walls on the ground floor, dig up 8 feet of foundation inside, remove all that material, replace it with better stuff and allow it to settle – and do similar on the outside – before residents could return. Imagine me sucking air through my front teeth before I say this… “that’s a serious job”. Serious jobs cost serious money.

Oh… by the way, Nama.

Lastly, a further tangental footnote: For the last few months there were three big sites in Dublin which many said were the only things keeping what’s left of the construction industry in the capital afloat. The Aviva Stadium, the new terminal at Dublin Airport and the new Mater Hospital building. The Aviva Stadium site closed last month and the terminal is finished in the next six weeks, I hear. Thankfully, at least for some of those in the construction sector, the Mater isn’t due for a while yet. 14,000 people or so in all between the three sites. A lot expect it to be their last contract in a while.

We’ve turned a corner lads!