Concrete Foundation Repair

Concrete is a durable material, but it has a natural enemy in Quebec's climate: water and freeze-thaw cycling. Water penetrates the porous surface of concrete and, when temperatures drop below freezing, expands by approximately 9% in volume. This internal pressure is called cryogenic pressure, and when it exceeds the tensile strength of the concrete surface, the outer layer physically flakes off — a process called freeze-thaw spalling.

In Laval, this process is accelerated by road salt and de-icing chemicals. Chloride ions from salt penetrate the concrete and attack the steel reinforcing bar (rebar) inside, causing it to rust. Rust expands to three to four times the volume of the original steel, cracking the concrete around it from the inside out — a process called reinforcement corrosion spalling. Homes along major Laval arterials and those with salt-treated driveways adjacent to the foundation are particularly vulnerable.

Acidic groundwater is the third culprit. Soils with decaying organic matter release carbonic and humic acids that slowly dissolve cement paste from the concrete matrix — a process called acid attack or carbonation. In areas of Laval with high organic soil content, foundations can show significant surface deterioration within 30–40 years.

Effective concrete repair requires correctly identifying the failure mechanism and selecting the appropriate repair material and technique. Surface application of a patch over unsound concrete is one of the most common and costly mistakes in the industry — the new material will de-bond within years without proper surface preparation to sound substrate.

For surface spalling and scaling, the deteriorated concrete is first removed by mechanical means — angle grinding, jackhammering, or hydrodemolition — back to sound, uncontaminated material. Polymer-modified cementitious repair mortars are then applied in layers, each carefully cured. These materials are formulated to match the thermal expansion coefficient of the existing concrete and bond chemically to the substrate.

For sections with rebar corrosion, exposed steel must be cleaned to bare metal and treated with a corrosion-inhibiting coating before any concrete is applied. In severe cases, rebar replacement may be required. For honeycombed concrete (areas that were improperly consolidated during original placement), the voids are typically filled with low-viscosity epoxy or cementitious grout injected under pressure.

Full section replacement is reserved for situations where the concrete is structurally compromised throughout a wall or footing section — a much less common scenario but one we handle with engineered shoring plans to safely support the structure during replacement.

The best investment after any concrete repair is a quality protective treatment to prevent recurrence. Several options exist depending on exposure conditions and aesthetic preferences.

Crystalline waterproofing admixtures react with cement and moisture to form insoluble crystals within the concrete pores, blocking water penetration from any direction and self-sealing micro-cracks as they form. Applied topically or mixed into repair mortars, crystalline treatments provide long-term moisture protection ideal for below-grade foundation conditions throughout Laval.

Penetrating silane/siloxane sealers repel water at the surface without forming a film that could trap moisture or peel. They are the preferred choice for above-grade exposed concrete surfaces subject to freeze-thaw cycling, providing 5–10 years of protection per application.

Elastomeric coatings bridge hairline cracks and provide a durable waterproof membrane on vertical and horizontal surfaces. They accommodate minor movement and resist UV degradation, making them suitable for visible foundation walls on homes throughout Chomedey, Fabreville, Sainte-Rose, and across Laval.

We serve all Laval neighborhoods for concrete foundation repair including Chomedey, Vimont, Duvernay, Fabreville, Sainte-Rose, Auteuil, Pont-Viau, Laval-des-Rapides, Sainte-Dorothée, Saint-François, Saint-Vincent-de-Paul, and Laval-Ouest. Free condition assessments available.