The Problem
A townhome owner in Mississauga noticed water seeping along the base of one basement wall after heavy rain, damaging the edge of newly installed laminate flooring in a recently finished basement. The homeowner had invested in the finishing project only months earlier, and the first sign of trouble was a slightly warped edge along one section of flooring, which on closer inspection turned out to be sitting in a thin layer of moisture that had gone unnoticed behind a piece of furniture.
Why It Happened
With shared walls on two sides of the property, exterior excavation access was extremely limited, ruling out a full exterior solution without significant cost and disruption to neighboring units. Our inspection confirmed the water was entering specifically at the floor to wall joint, a pattern well suited to interior drainage rather than full exterior excavation, and consistent with a property where exterior grading and a shared party wall configuration concentrated water runoff toward this particular section of foundation.
Our Process
- Removed a section of flooring and baseboard along the affected wall to access the floor slab, working carefully to preserve the surrounding finished flooring
- Cut and excavated a trench along the interior perimeter at the point of water entry
- Installed a perforated drainage pipe wrapped in filter fabric, connected to a new sump pit and pump sized appropriately for the townhome’s drainage demand
- Applied dimple board along the base of the wall to direct water into the drainage channel rather than across the floor
- Restored the concrete floor along the trench and coordinated flooring repair timing with the homeowner’s original flooring contractor
- Tested the completed system under simulated conditions before considering the project finished
Results
The project was completed within two days, with minimal disruption to the rest of the finished basement, and the homeowner’s flooring contractor was able to seamlessly patch the affected section within the week. The homeowner has reported no further water intrusion since installation, and the new sump pump has been tested through several subsequent storms without issue, giving the homeowner confidence in the finished space they had originally worried they might need to redo entirely.
The project also highlighted an important lesson for other townhome owners in similar shared wall situations: exterior access limitations do not have to mean a basement’s water problem is unsolvable, it simply means the right solution looks different than it would for a detached home with open yard access on every side.
Related: Sump Pump Services · Basement Flooding Repair