Basement Waterproofing Cost Calculator for St. Louis, MO
Wondering what an interior drain, a new sump pump or crack sealing might cost for a basement in St. Louis, MO? Four quick questions produce a rough range from published national rates. You won't be asked for a name or address, and the result works as a yardstick for a contractor's written estimate rather than a price.
What You'll Need
Before you start: have a rough idea of the basement's floor area and of where water shows up. The calculator turns floor area into an approximate length of foundation wall, keeps the share you mark for a drain, and prices those feet at the interior perimeter drain rate. It then adds sump pump installation and epoxy crack injection if your answers call for them. Many City homes are two-family or four-family brick flats with one basement under several units (Census survey), so size the whole basement, not just your own unit's footprint.
| Cost row | Figure | Source (year) |
|---|---|---|
| Typical basement waterproofing project | about $3,000 to $10,000 (average about $5,000) | Fixr national (2026) |
| Interior perimeter drain, per linear foot | $40 to $120 | Fixr national (2026) |
| Sump pump installation | $600 to $2,500 | Fixr national (2026) |
| Epoxy crack injection, per crack | $250 to $1,000 | Fixr national (2026) |
| Waterproof paint or sealant, per sq ft | $1 to $8 | Fixr national (2026) |
Only the drain, pump and crack rows feed the math; the project and sealant rows are context. All five are national figures, not St. Louis prices. Three things stay out of the result: digging along the outside of the foundation, backflow valves and sewer lateral repairs. For backups caused by MSD's system, MSD's Sewer Backup Prevention Program may pay for a backflow device, and the City and many County cities run lateral repair programs; the cost guide covers what that work runs when paid privately.
What to Do Next
To see how this range holds up in your own basement, get a written estimate. Send the short form, and one independent local contractor will reach out, arrange a visit and write up the scope and price. In the meantime, the cost guide explains what pushes a total up or down, and the wet basement checker can help narrow down where the water gets in.