Newsletters

381

SNC-Lavalin inc. c. Deguise: Excluding the Risk Related to Pyrrhotite

On April 6, the Court of Appeal of Québec rendered its decision in SNC-Lavalin inc. (Terratech inc. et SNC-Lavalin Environnement inc.) c. Deguise, 2020 QCCA 495.

Considering the importance of this decision for both the construction and insurance industries, RSS offers a series of newsletters discussing the main issues at stake. This is one segment of the complete series found here.

Approximately 800 property owners in the Trois-Rivières area have brought a claim against contractors and formworkers (for the construction of houses and foundations), a geologist who had prepared certain reports on the quality of the aggregate used for the concrete foundations, as well as his employer (SNC Lavalin), the concrete mixers (CYB and BL) and the company operating the quarry from which the aggregate was extracted (B&B), as well as their insurers. The property owners alleged that their houses suffered from a major defect, namely the swelling of the concrete, affecting the foundations.

Before the Superior Court, some insurers (notably Northbridge (Lombard) and AIG (Chartis) insurer of Bellemare (shareholder of BL) and CYB, as well as RSA insurer of some contractors) pleaded an exclusion clause denying coverage for property damage resulting in whole or in part from pyrite or aggregates containing pyrite.

Northbridge had added this exclusion by way of an addendum in Bellemare’s insurance policy for the period from December 1, 2008, to December 1, 2009, and in CYB’s policy for the period from March 31, 2009, to March 31, 2010. AIG had added a similar exclusion for the period December 1, 2008, to December 1, 2009.

However, the Superior Court ruled that the swelling of the concrete was caused by the oxidation of the pyrrhotite present in the aggregate used for the concrete foundation. Indeed, the Court accepted the evidence that the only cause of the damage was the oxidation of pyrrhotite, an ore different from pyrite, even though both substances were present in the aggregate: “It is a different substance. There is nothing in the evidence to allow the Court to conclude that the damage resulted in whole or in part from the pyrite, quite the contrary. The experts’ unanimous finding is that the damage is caused by the oxidation of the pyrrhotite” [our translation; SNC-Lavalin c. Deguise, par 845, quoting the judgment of the Superior Court, Deguise c. Montminy, 2014 QCCS 2672, par 1959]. Thus, the Superior Court concluded that these exclusion clauses could not apply.

The Court of Appeal studied the matter of the exclusion clause raised by Northbridge against Trois-Rivières Cimentier inc. and raised by RSA (which insured seven contractors). It should be noted that the cause of the swelling, namely the oxidation of the pyrrhotite, was not challenged before the Court.

For both insurers, the exclusion clause concerned damages caused directly or indirectly by pyrite or materials containing pyrite. Furthermore, both argued that the clause was clear and that the exclusion applied as long as the damages were caused by an aggregate that contained pyrite.

The Court of Appeal found that the wording of the clauses was ambiguous given its opposite interpretations by the appellants and respondents. In the absence of evidence as to the parties’ intent at the time the addendum, the Court ruled that the ambiguity be interpreted in favour of the insured, in accordance with the rule in such matters. In sum, the Court of Appeal concluded that the insurance companies did not meet the burden of proving that the exclusion clause applied to damages caused by pyrrhotite.

381

Articles in the same category

Not So Intelligent!

Since the widespread adoption of artificial intelligence tools, growing concerns have emerged regarding their use in judicial proceedings. Recent decisions have relied on section 342 of the Code of Civil Procedure to sanction parties who make improper use of such tools. More specifically, this provision has been invoked on several occasions to address the use or citation […]

So? Is it settled or not?

In an interim decision in Djaferian v. Spanoudakis,rendered on February 20, 2026, the Superior Court had to determine whether an offer made 15 months earlier, prior to the institution of proceedings, could still be accepted and result in a transaction. Summary of Facts and Timeline The Plaintiff, a co-owner who sustained water damage to his private […]

Office Parties and the Employer’s Duty to Prevent Harassment

In De Sousa and Corporation interactive Eidos, 2026 QCTAT 4, the Quebec Administrative Labour Tribunal (ALT) appears to have broadened the scope of an employer’s obligation to prevent harassment. The decision arose from a complaint filed by a former employee who had been sexually assaulted at her home by a colleague following an office party organized by the […]

Should Economic Losses Be Considered Property Damage?

The Quebec Court of Appeal in Zurich, Compagnie d’assurances SA c. CRT Construction inc., recently overturned the Superior Court’s decision on the interpretation of a construction insurance policy. Facts CRT Construction Inc. (“CRT”) was retained by the City of Montreal (“City”) to perform major construction work at the Atwater water treatment plant. At the City’s request, CRT […]

The Court of Appeal delves deep into the parties’ intentions and claimant hits a wall…

The Facts In the context of a project for the construction of a ten-storey condo building, the excavation contractor subcontracts the design and installation of a Berlin-type retaining wall (the “Wall”) to Phénix Maritime inc. (“Phénix”) which, in turn, subcontracts the design to Les Investigations Marcel Leblanc inc. (“IML”). Problems arise that substantially delay the […]

New CAI Guidance on Preventing Confidentiality Incidents: A Practical Roadmap for Businesses in Quebec

On January 30, 2026, Quebec’s privacy regulator, the Commission d’accès à l’information (“CAI”), published fresh guidance aimed at strengthening how organizations prevent confidentiality incidents involving personal information. Confidentiality incidents are one of the most significant privacy risks facing organizations today. In Quebec, these incidents are governed by several laws, including the Act respecting the protection […]