Pyrite inspection & testing
in Montreal and surrounding areas

For residential and commercial properties in Montreal, on the North Shore and the South Shore.

What is pyrite?

What is pyrite and why is it a concern?

Pyrite is a mineral found in the backfill (crushed stone) under the concrete slab. When exposed to moisture and oxygen, pyrite can oxidize and swell, causing significant damage to building foundations. This problem is common in areas such as Montreal, the North Shore and the South Shore, where particular geological conditions increase the risk of pyrite-related damage.

What is a pyrite test?

This involves taking a sample of the backfill (crushed stone) located under the concrete slab (floor) to determine its petrographic index of swelling potential (IPPG) and whether there is a potential for swelling that could damage the building.

What we check

We also check if the concrete slab is affected by sulfation and, where possible, if the natural ground has a potential for swelling linked to pyrite. Our services are available throughout Greater Montreal, including the North Shore and the South Shore.

How pyrite can affect your building's structure

The swelling of crushed rock due to the presence of pyrite can cause cracks and heave in the concrete slab and affect foundation walls. Ultimately, this can compromise the safety and value of your property. This phenomenon is particularly concerning in many areas of Montreal, the North Shore and the South Shore.

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Affected geographic areas in
Montreal, North Shore and South Shore

Fill materials exhibiting swelling due to the presence of pyrite are found throughout the Greater Montreal area. Pyrite issues are not limited to older buildings: even properties built after 1999 can be affected, as the National Building Code does not require builders to use DB-certified backfill.

Montérégie (South Shore of Montreal)

The region with the highest concentration of pyrite-related issues:

Longueuil (Saint-Hubert, Greenfield Park, Vieux-Longueuil)
Brossard
Boucherville
Saint-Jean-sur-Richelieu
Chambly
Saint-Bruno-de-Montarville
Saint-Basile-le-Grand
Candiac
La Prairie
Châteauguay
Delson
Sainte-Catherine
Saint-Constant
Saint-Amable
Varennes

On the Island of Montreal and in Laval

Certain sectors are particularly at risk:

Rivière-des-Prairies
Pointe-aux-Trembles
West Island: Pointe-Claire, Dollard-des-Ormeaux (DDO), Beaconsfield, Kirkland, Pierrefonds-Roxboro, Baie-D'Urfé, L'Île-Bizard–Sainte-Geneviève

In Laval, cases of pyrite have been reported in:

Sainte-Dorothée
Fabreville
Chomedey
Laval-Ouest
Laval-sur-le-Lac

Lanaudière and Basses-Laurentides

In Lanaudière, affected municipalities include:

Repentigny
Le Gardeur
L'Assomption
Terrebonne
Mascouche

In the Basses-Laurentides, certain towns have known issues:

Blainville
Boisbriand
Mirabel
Rosemère
Sainte-Thérèse
Saint-Eustache

How can we help you?

If you suspect pyrite damage or want to make sure your property is safe, contact our partner Multitest today for a professional assessment.

Visit Multitest's website

Pyrite inspection & testing in Montreal and surrounding areas