Its important to be aware of the pyrite problem on the south shore of montreal. In scientific circles, awareness of the problems caused by the swelling of rocks containing pyrite dates quite far back. The first cases were reported around 1930 in the United States. In Canada, a very explicit text on pyritic clays in the Ottawa region was published in 1975 by the National Research Council in the Construction Digest. In the Montreal region, cases of swelling were reported as early as 1985.  Before buying an older house on the south shore of montreal call your excavation professional Pyrite Pro.

The swelling of backfill can not be harmful  to your health .The Montérégie Public Health Department says the quantities of sulfuric acid are too minute to cause health problems.

If a building is suspected of having a pyrite problem some of the typical observable signs are:

  • Heaving (lifting) of a floor slab resulting in slopes and cracks.
  • Cracks to concrete floors/tiles.Uplift at external door thresholds.
  • Doors catching on floors.
  • Cracks over doors on internal walls.
  • Ground floor stud partitions with cracks, bulging of plasterslabs.
  • Horizontal cracking externally at DPC level.

Cracking or fractured garage and basement foundations walls, bulging floors and whitish particles often indicate you have a pyrite problem. Getting a lab test done can show if any high levels of pyrite is present in the rock. A lab test can cost 250.00 to 600 dollars on the south shore of Montreal.

If high levels of pyrite are present in the rock beneath the concrete floor or in the concrete of the foundation itself, it will oxidize on contact with moisture and oxygen. This oxidation generates sulphuric acid, a substance that causes rock to burst and fill to swell. The process of expansion places enormous pressure on overlying concrete and will eventually damage it.

The same pyrite removal technique is also employed to remove fill contaminated with such substances as heating oil. Any existing damaged concrete must be crushed in such and the stone removed from the contaminated fill. We use miniature excavation equipment to maximize the effectiveness of our operations and to ensure total safety.

New fill using quality stone called 3/4 net DB whith we spread and compacted and then pour the new concrete slab.

The price for a complete pyrite overhaul on the south shore of Montreal will range from 18.00$ to 24.00$ dollars a square foot. any question or for a free appraisal call us 514.594.2897

The Property valuation of a house damaged by the swelling of backfill in brossard or other citys could ask to have his property valuation lowered. For the owners who are not planning immediate repair work, this could mean savings of several hundred dollars in tax yearly. Contact your municipality to find out what procedure to follow in obtaining a re-evaluation. or get the work done buy an excavation contractor