Below-Grade Waterproofing

What This Service Involves

Homes built into Puget Sound's sloping lots often have walls that hold back saturated soil for months at a time. Below-grade waterproofing applies membranes, coatings, and drainage layers to those walls so water is directed away instead of pushing through the concrete. We tailor the approach to your soil, water table, and whether the space is finished living area or storage. Done correctly, it keeps basements and daylight-basement rooms dry through the wettest winters. Every assembly we install meets code and is backed by our WA L&I licensing.

Benefits

Prevents seepage through foundation walls and cold joints; Relieves hydrostatic pressure that cracks and bows concrete; Protects finished basement space and flooring below grade; Preserves indoor air quality by keeping dampness out; Extends the useful life of the foundation

Our Process

1) Assess water entry points, grading, and soil conditions around the foundation; 2) Excavate or prep interior walls as the design requires; 3) Apply waterproof membranes and install drainage board or channels; 4) Backfill, restore grade, and confirm water is routed to a proper outlet

What Affects the Cost

Depth and length of the wall being treated; Interior versus exterior approach and excavation needs; Soil type and severity of the local water table; Condition of existing concrete and any crack repair; Tie-in to drains, sumps, or discharge lines

Best Time of Year

Exterior below-grade work goes smoothest in the drier summer stretch when excavations stay stable, while interior methods can proceed in any season.