Submission by Dublin City Council and Ballymun Regeneration Limited

to the

Joint Oireachtas Committee on Environment, Transport, Culture and Gaeltacht

11th October 2011 Topic

“The cost of restoring the structural integrity of houses damaged by the use of Pyrite in building materials”

1 Contents

Pyrite: An Introduction Page 3

Pyrite in Dublin City Council Housing Projects Page 4

Pyrite in Ballymun Regeneration Projects Page 7

2 Pyrite: An Introduction

Pyrite is a mineral, occasionally present in stone, but when exposed to the earth’s atmosphere and or water becomes unstable and produces sulphuric acid which in turn reacts with calcite formations in the rock. This creates Gypsum Crystals within the rock leading to gradual expansion and bulging over a prolonged period of years. The sulphuric acid can also unravel the structural integrity of the concrete and attack reinforcing steel. Because of the volatile nature of this mineral, its presence is usually banned from construction materials; in particular clause 804 infill material which is commonly specified to be used in the construction of roadways and as infill material under the floors of buildings, specifically requires stone that is inert and therefore free from pyrite.

A major construction problem occurred in Canada in the 1980’s and 1990 due to pyrite in the infill under the floor slab of buildings. Since then the phenomenon has become quite well known amongst building industry professionals. The unstable nature of the mineral causes expansion in the stone infill under the building; such infill is already very compacted in order to give stability to the building. This rogue mineral thus causes outward and upward heave putting upward pressure on the floor slab and outward pressure on the external wall, resulting in bulging of the floor slab and cracking and buckling of the external supporting structural walls; it is usual for internal stud partition walls also to be crushed and cracked and for doors to be jammed by the pushed up floor slab.

Damage is progressive over many years and what is initially thought to be normal minor settlement or drying out of plaster can turn out to be a major pyrite problem which will lead to serious damage to the building. The speed at which this happens seems to be related to the percentage of active mineral in the stone, the atmosphere and dampness of the local climate and perhaps the exposure of actual stone used in a specific building to rain etc. Pyrite does not have any known direct adverse effect on human health.

3 Pyrite in Dublin City Council Housing Projects

The presence of Pyrite in Dublin was first confirmed in mid 2008 in the Avila Park travellers Housing Scheme in Finglas. Phase 4 of the development, which consisted of six houses and a community centre, was completed in 2005, and exhibited unusual defects within a year of completion. These defects initially consisted of plaster cracking and spalling, then progressive cracking above window heads in external walls. The defects were eventually attributed, following investigation, to excessive Pyrite in imported stone fill.

Cracking in external wall of typical Avila Phase 4 house

Also in 2008 Dublin City Council Engineers investigating a leaning wall in the Griffith Heights housing development in Finglas noticed that the footpaths in that development displayed similar defects to the Avila Park footpaths, and confirmed the presence of excessive levels of Pyrite in the stone fill. Sampling of stone in the houses revealed similar levels of Pyrite, although progression of damage has been slow in comparison with the Avila Park Houses.

Leaning wall caused by heave of footpath at Griffith Heights

4 The Griffith Heights development consists of 35 affordable houses, 15 social houses, and 33 senior citizens apartments in several blocks. Footpaths in the development have exhibited heave in excess of 35mm. Building damage, to date, is slight.

Heave of infill footpath at Griffith Heights

Review of developments

The findings in Avila Park and Griffith Heights prompted a review of recently built Dublin City Council housing stock. The review was carried out by Housing Department staff using year of construction, location, and observable defects as indicators of possible problems, and in June 2009, the presence of excessive levels of Pyrite in stone fill was confirmed in the Clancarthy Court Senior Citizens development in Donnycarney. The development consists of 20 senior citizens flats in three no. two-storey blocks. Defects had been observed within 18 months of completion, but were not attributed to Pyrite until stone samples were taken in 2009. Structural damage in this development was significant, with floor heave in excess of 40mm.

Floor heave in unit at Clancarthy Court showing bent worktop confined by wall tiles.

5 Sampling of stone and testing is expensive, and disruptive to occupants. A further development in Ballybough has been confirmed with excessive levels of Pyrite. The development consists of 69 new units, although the extent of the problem is not yet known. Investigations at this location are ongoing. All confirmed instances of Pyrite are located on the north side of the city.

Current position

All of the affected developments were constructed by contractors on behalf of Dublin City Council. Defects arising in a development, whether related to Pyrite or otherwise, are dealt with under the provisions of the particular contract. Resolution of these issues is complex, involves mediation and confidentiality is generally required.

All developments with confirmed Pyrite problems are constantly monitored by Housing Department staff. The safety of occupants is of paramount importance, and while manifestation of damage in Pyrite affected houses does not usually cause safety concerns, it has been considered necessary to demolish two walls at Griffith Heights with excessive lean. In addition, the Avila Park houses were detenanted due to the rapid progression of damage, which included insecure ceilings in one house. At present, tenders have been received for the repair of these houses with an anticipated site start this month. The tender price is €663,000 approx.

Dublin City Council have entered into a mediation process under the contract with the contractor for the Griffith Heights development in an attempt to have the remediation works carried out without recourse to expensive legal action.

Remedial works to the Clancarthy Court development commenced in May 2011, and it is expected that these will be complete by January 2012. The estimated all in cost is €700,000 approx the Department of the Environment, Community and Local Government granted approval to these works at Clancarthy Court as the contractor went into liquidation shortly after the development was completed.

Dublin City Council has retained experts in the areas of Geotechnics and Ground Chemistry to advise on Pyrite related issues, including remediation. The remedial works at Clancarthy Court have proved successful to date, and similar results are expected in Avila Park.

6 Pyrite in Ballymun Regeneration Projects

The first problem for BRL arose in the Reco Building, a community, youth and childcare facility developed by BRL. The contractor was J.E.C. Ltd who fixed the apparent snags, which when they recurred, were further investigated. Cores were drilled, samples taken and following scientific chemical analysis, the abundant presence of pyrite was confirmed. The contractor arranged for the removal and replacement of all the aggregate under the floor slab; this required, removal of kitchens, doors, stairs, sanitary ware, internal stud walls, etc; cutting the concrete floor slab into 600 x 600mm sections, thus removing the full slab and allowing the removal and replacement of the pyrite material. The fixing of all cracks, the replacement of stairs, fixtures and fitting, and the redecoration of the building was then completed; footpaths and filling around services within the curtilage of the building plus the removal of hardcore from the entire courtyard area also required similar remedial works.

The building needed to be vacated while all this work was going on. The source of the stone material was known and proven to be a quarry at Bay Lane near Blanchardstown operated by Irish Asphalt (part of the Lagan Group of companies). The contractor (JEC Ltd) who fixed the Reco building at their own expense took proceedings against Irish Asphalt for full recovery of cost and expense. The case lasted 58 days in High Court (another pyrite case, involving Menolly Homes which was eventually settled lasted 159 days) Justice Charlton found fully for the contractor. However, the quarry operator has applied for permission to appeal the decision to the Supreme Court, and for a stay on payment of interim damages (€1m damages and €½m cost) pending the outcome of the Supreme Court Hearing.

The Quarry Company has also lodged (July 2011) affidavits with High Court asserting that it has no unencumbered assets and is therefore not in a position to pay either damages or costs. The Quarry Company also state in an affidavit that it has made a deal with its insurers on the Menolly case, in full and final settlement, and that its insurance cover is therefore exhausted. In the meantime 3 other BRL projects have turned out to have pyrite problems; Sillogue 4, 124 housing units (not yet occupied); Carton Terrace, 94 units occupied and Owensilla 58 units also occupied. The Sillogue 4, contractor is J.E.C. Ltd, the other 2 were

7 built by a different contractor. All are either wholly or partly affected by pyrite from the Bay Lane Quarry.

BRL is arranging to carry out remedial works in Sillogue 4, (124 units) with the Contractor JEC (direct cost €10.5m approx). Tests are continuing to be carried out on other 2 sites, but it seems certain from the results of initial tests that some of these houses have a problem with pyrite. BRL and DCC are keeping residents informed. Remedial works will be necessary in all affected houses.

BRL is currently evaluating its legal position with a view to litigation against Irish Asphalt, the Lagan Group of companies and their insurers. A decision is imminent.

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