Serving Oakland
Groundwater & Basement Water Intrusion in Oakland, CA
Basement seepage, failed sumps, and hydrostatic pressure against the foundation are extracted and dried, and the path from the ground is identified so the loss does not repeat. Groundwater and basement seepage are extracted and dried only after the path from the soil is identified — a wall, a slab, a drain, or a failed sump. Drying the interior without stopping that path returns the same water to the same floor.
Frequently asked questions
The slab has cracked and doors have stopped closing. Is that water?
On filled ground the more likely explanation is settlement, with water following it. Fill placed over soft material consolidates unevenly across decades, so parts of a building move at different rates and joints open at the slab, around openings, and where additions meet the original structure. Those openings then admit water in the next storm. Sealing them without recognizing the movement means sealing something that will keep opening.
Water comes out of the hillside rather than off the street.
On a graded terrace that is the usual mechanism. Rain soaks into the flatter ground above, moves down through the fill until it meets denser material, and then travels sideways until it emerges at a cut face partway down the slope. It arrives under pressure rather than running across the surface. Interception above the house is what changes it, and it needs to be designed for that specific slope rather than copied from a neighbor.
How do we decide between fixing drainage and fixing the building?
Establish what is moving first, because the sequence matters. If ground is settling or a slope is creeping, work done on the building will be undone. A geotechnical assessment on either kind of ground here is worth its cost before committing to structural repair, and it also tells you whether the water is a cause or a symptom. Doing it the other way round is how people pay twice.
The same questions, in context, on the Oakland mold removal page.