Repair of foundation cracks

Depending on the type of cracks encountered, immediate repair is not always necessary. An active crack must, in most cases, be injected, whereas this is not necessarily the case for a passive crack. If no infiltration comes from it, the owner can then choose not to repair it.

However, a passive foundation crack does not mean zero risk. The likelihood of water infiltrating through foundation walls remains, but the risk is rather low.

Repair techniques: High or low pressure injections vs Steel reinforcement

The choice of technique to be used is determined by the width of the crack and not by the type encountered (active or passive). A low pressure injection is performed when a crack is large (⅛ inch and over) while a finer crack will be injected at high pressure. The use of extensible polyurethane is generally recommended, particularly because of the flexibility of its resin compared to that of epoxy.

It is also important to note that, in the case of active cracks, repair by laying reinforcement or steel piles is often required. Since this type of crack is usually due to poor soil composition, such a repair will solidify the house foundation and prevent the crack from reopening.

Inside vs Outside repairs

Injection can be done from both inside or outside the wall and will depend on factors such as the width of the crack, its location, accessibility, interior finishing of the basement, landscaping, etc.

Need an expert for concrete repairs in the West of Montreal?

Whether you live in the West of Montreal, Vaudreuil-Soulanges or Valleyfield, you can count on Fondation & Fissure St-Amant team’s expertise for all your foundation reinforcement and repair work. We will meet your needs by offering you tailor-made solutions that respect your budget.

Feel free to contact us for more information. We will be happy to answer your questions.


Work and materials for our Foundation waterproofing and French drain installation services are covered by a 15-year warranty. Crack repairs are guaranteed for a 10-year period. Our warranties are transferable upon the sale of the property.
Certain conditions may apply.