Updated: Nov 3, 2018
WHAT IS PYRITE? Pyrite is a very common, naturally occurring mineral. Traces of it are naturally found in the sedimentary rock that is used to make crushed stone for backfill used in construction. If the amount of pyrite in the stone is below a certain proportion, no problems occur. However, if the amount of pyrite is greater combined with certain atmospheric conditions then problems can arise resulting in structural damage to a property.
WHAT ARE THE SIGNS OF PYRITE DAMAGE?
If a building is suspected of having a pyrite problem some of the obvious signs are:
Heaving or lifting of a floor slab resulting in slopes and cracks
Cracks to floor tiles/damage to floor finishes
Bulging of plasterslabs
Horizontal cracking externally at DPC level
Uplift at external door thresholds
Doors catching on floors
Cracks over doors on internal walls
Ground floor stud partitions with cracks
WHAT AREAS ARE AFFECTED BY PYRITE?
The confirmed areas that have been affected by pyrite-heave are mostly concentrated in:
North Co. Dublin
North Co. Wicklow
REPAIR OF PYRITE AFFECTED BUILDINGS The repair process is disruptive and costly. The work essentially involves taking up the concrete ground floor of the property, removing all the fill from under the floor, replacing it with new fill, and reinstating the floor, complete with damp proof
membranes, radon barriers, below ground services, etc. This work will almost certainly require the property to be vacated, unless only a new extension is affected.
The work will need to be carefully specified and properly supervised, and should be carried out under the supervision of a suitably qualified professional.
COSTS OF REMEDIAL WORKS Costs will vary from house to house depending but it is estimated that at a minimum, the cost of repairing a single pyrite-affected house may be in the region of €20,000. This cost could be significantly higher if there are high cost finishes and fittings to be removed and replaced, or if any structural instability has occurred as a result of the damage to date.
IS PYRITE TESTS COVERED IN MY BUILDING SURVEY?
A detailed Pyrite test is NOT covered within your building survey. However, if the Surveyor suspects there may be signs of Pyrite, they will inform you and then you should engage with an independent engineer and pyrite resolution expert to conduct further tests.