This substance used to be called fools gold and was also involved in firing old weapons. It is often found in quarries and may be mined mixed with regular stone for building purposes. But it chemically reacts and is oxidized. This causes swelling, cracking and heaving of walls as it expands when oxidized.

Griffith Heights

There are 35 affordable houses, 15 social houses and 33 senior citizens units affected by pyrite infill in the Griffith Heights development which is only built recently. Northside Construction was involved and has agreed to go to mediation with Dublin City Council to resolve the financial issues. This is a better solution than going individually to litigation.

Currently, the engineers have told councilors that the houses are livable in and are not a danger. The costs of restitution are likely to be about 40,000 euro per residence and run into millions of euro, the likely cost will be about €3.2 million. Remedial work usually lasts 12 to 14 weeks per house. The householders and the City Council are innocent victims of construction quarry material misuse. The other areas in Northwest affected by Pyrite are the Silloge 4 scheme in Ballymun Regeneration involving 124 housing units, Avila Park Traveller accommodation near Cappagh Hospital and the RECO building for youth services at Ballymun Town Centre.

Other well known pyrite examples are the problems at Beaupark at Clongriffin and also at Drynam near Kinsealy involving Menoly Homes.