An open sump pit is a radon chimney. We seal it in one visit.
Gasketed sump lids, sealed drain-tile connections, and 6-mil+ crawlspace membranes — as a standalone service or the sealing half of a full mitigation system.
From $350 · Every seal smoke-tested before we leave.
The problem
Most Johnson County basements drain to a sump pit tied into perimeter drain tile — which means an open or loose-lidded pit is a direct, engineered pathway from the soil around your entire foundation into your living space.
The same goes for the dirt-floor crawlspace under that 1920s addition: hundreds of square feet of exposed soil off-gassing into the house, connected to the finished basement by a doorway with no door. A mitigation fan fighting an open pit and a bare crawlspace is a fan running uphill.
We install gasketed, bolted sump lids with sealed cord and discharge penetrations (pump service access preserved), and line crawlspaces with overlapped, taped, mechanically-fastened vapor barrier — then smoke-test every seal. Standalone, or as the sealing stage of a full system.
What’s included
- Gasketed clear sump lid — pump visible and serviceable without breaking the seal
- Sealed penetrations for discharge pipe, cords, and water lines
- 6-mil or heavier crawlspace vapor barrier, seams overlapped and taped, edges sealed to walls
- Slab crack and expansion-joint caulking where accessible
- Smoke-test verification of every seal before we leave
Our process
- 1We photograph and measure the pit and any crawlspace during the quote visit
- 2One-visit install of lid, penetration seals, and membrane
- 3Smoke test confirms the seals hold under depressurization
- 4Optional follow-up CRM test to measure the improvement
Transparent pricing
| Gasketed sump lid, sealed and smoke-tested | from $350 |
| Crawlspace vapor barrier | from $4/sq ft installed |
| Sealing package added to a mitigation install | bundled into the flat quote |
Frequently asked questions
Will sealing alone get me below 4.0 pCi/L?
Sometimes, when the starting number is modest — say 4 to 6 pCi/L — and the pit was the dominant entry point. At Iowa-typical readings near 10, sealing is usually stage one of an active system, not a substitute. We'll tell you which case you are before you spend anything.
Can my sump pump still be serviced with a sealed lid?
Yes. We install clear, gasketed lids with bolted access — you can see the pump working, and any plumber can unbolt the lid and re-seat the gasket in minutes.