Two approaches
Interior drainage is the common choice. A strip of floor is cut out along the walls, a perforated pipe is laid in stone at the footing, a membrane goes against the bottom of the wall, and the line runs to a sump pit. Water still reaches the wall, but it is led to the pump instead of across the floor.
Exterior waterproofing means digging down to the footing, cleaning the wall, applying a membrane and drainage board and laying a footer drain before backfilling. It stops water at the outer face and suits walls with landscaping room and no decks or driveways in the way.
Which one fits your house
| Situation | Usual direction |
|---|---|
| Water at the floor joint around most of the basement | Interior drain to a sump |
| One wall leaking, open yard outside | Exterior work on that wall |
| Finished basement you do not want torn up | Exterior work, or interior work done before refinishing |
| Water only after storms, from one corner | Check gutters, downspouts and grade first |
Start outside, even for an inside job
Gutters that overflow, downspouts that end at the wall and soil sloped toward the house send more water into the clay than any drain should have to handle. We look at all of it at the inspection and fix the cheap parts first. Some basements need nothing more.
Where the drain ties into plumbing, or a pump discharges to a sewer line, that connection is made by a licensed plumber under the right permit. The waterproofing side we handle ourselves.
Questions we hear about basement waterproofing
Is interior waterproofing really waterproofing?
It manages water rather than blocking it at the wall. For most St. Louis basements that is the reliable fix, because it relieves the pressure that pushes water through.
Do I need a permit for waterproofing?
Exterior excavation and some interior work need permits depending on the city or county. We check for your address and file where it is required.
Will waterproofing stop a wall from bowing?
Relieving water pressure helps, but a wall that has already moved also needs to be held. See bowing wall repair.
