Interior Drainage System

What This Service Involves

When exterior excavation is impractical, an interior drainage system manages water from within the basement. We cut a channel along the perimeter of the slab, set perforated drain pipe in gravel, and route everything to a sump basin that pumps water safely away. This method is well suited to finished-basement conversions and daylight basements common across the Sound. It handles both wall seepage and rising groundwater without disturbing your yard. Our installations are permitted where required and built to Washington code.

Benefits

Captures water from walls and the floor-to-wall joint; Works without excavating the exterior of the home; Ideal for finished or soon-to-be-finished basements; Keeps the slab and framing dry year-round; Integrates cleanly with a sump pump for automatic removal

Our Process

1) Map water entry and mark the drain path around the perimeter; 2) Saw-cut and remove a channel in the slab edge; 3) Lay perforated pipe in washed gravel and connect it to a sump basin; 4) Patch the slab, install the pump, and test the full loop

What Affects the Cost

Perimeter length of the drainage run; Concrete thickness and cutting difficulty; Number of sump basins and pump capacity; Discharge routing and distance to a legal outlet; Any wall vapor barrier added to the system

Best Time of Year

Interior drainage can be installed in any weather, making winter, when leaks reveal themselves, a practical time to act.