Basement Waterproofing

Laval sits on an ancient seabed of dense marine clay — a soil type that holds and slowly releases water like a sponge. During spring snowmelt and heavy rainfall, the water table rises rapidly, and saturated clay exerts enormous hydrostatic pressure against basement walls. The result: water pushes through the path of least resistance — cracks, cold joints, floor-wall joints, and tie rod holes — into your living space.

In neighborhoods like Chomedey, Duvernay, and Laval-des-Rapides, where the water table can rise to within a few feet of the surface during peak spring conditions, even recently built homes experience water infiltration. Older homes in Pont-Viau, Auteuil, and Saint-Vincent-de-Paul often have deteriorated original waterproofing membranes that no longer perform their function.

The health implications are significant. INSPQ studies have linked basement moisture to elevated rates of respiratory conditions in children, particularly asthma. Mold spores spread through HVAC systems to every room in the home, not just the basement. Addressing the moisture source — not just surface mold — is the only effective long-term solution.

Basement waterproofing is not a one-size-fits-all solution. The right approach depends on your home's construction, the source of water, your budget, and landscaping constraints.

Exterior waterproofing is the most comprehensive solution. It involves excavating around the full foundation perimeter, applying a new waterproofing membrane to the exterior wall surface, installing a dimple drainage mat, and laying a new perimeter drain (French drain) at the footing level. Exterior work stops water before it ever contacts the wall — it is the closest to a permanent solution. However, it requires significant excavation, typically costs more, and takes 3–7 days depending on home size. For homes throughout Sainte-Rose, Fabreville, and Sainte-Dorothée, exterior waterproofing is often the recommended approach when drainage conditions allow.

Interior waterproofing manages water that has already entered the wall system. A channel is cut around the basement perimeter at the floor-wall joint, a drainage membrane or channel is installed to collect infiltrating water, and the water is directed to a sump pit equipped with a submersible pump. Interior systems are less invasive, cost-effective, and can be completed in 1–3 days without disrupting landscaping. For most homeowners in Vimont, Saint-François, and Laval-Ouest, an interior drainage system with a quality sump pump provides excellent protection.

Every comprehensive waterproofing system incorporates a sump pump — the mechanical device that actively removes collected water from your home. Modern sump pump systems have evolved significantly: dual-pump configurations provide redundancy in case of primary pump failure; battery backup systems keep pumps operational during power outages (which often coincide with the worst storms); and smart monitoring systems send smartphone alerts when the water level rises abnormally or a pump fails.

For homes in Laval, we recommend at minimum a primary pump rated for your home's water volume, plus a battery backup system. Areas with high water tables like Chomedey and Duvernay benefit from dual-pump primary systems for added reliability. Annual maintenance — testing the pump, cleaning the pit, checking the discharge line — extends pump life and ensures the system performs when you need it most.

All our waterproofing installations are backed by transferable written warranties. Our service area covers the entirety of Laval including Chomedey, Vimont, Duvernay, Fabreville, Sainte-Rose, Auteuil, Pont-Viau, Laval-des-Rapides, Sainte-Dorothée, Saint-François, Saint-Vincent-de-Paul, and Laval-Ouest.