What this covers
Most radon mitigation is sub-slab depressurization: the installer drills a suction point through the basement slab, removes a small pit of soil beneath it, and runs a sealed PVC pipe to an inline fan outside or in the attic, then up to vent above the roofline. The fan keeps the space under the slab at lower pressure than the house so soil gas is drawn out instead of in. Cracks, gaps and the sump lid are sealed, a gauge on the pipe shows the system is running, and a follow-up test measures the result. Crawlspaces get a sealed membrane with the suction under it.
When to call
- A radon test result you want to bring down.
- A sale where mitigation was agreed after testing.
- An existing system whose fan has stopped or whose gauge reads flat.
What to expect
- DiagnoseThe installer checks the slab, sump and foundation and picks the suction point and pipe route.
- InstallThe suction point is cored, the pipe and fan are installed, and the vent run above the roofline.
- SealAccessible cracks, gaps and the sump lid are sealed so the system draws from under the slab.
- RetestA follow-up test is run after the system has been operating, and the gauge reading is recorded.
Get a certified company
Look up a certified company by ZIP code. Every company's license, insurance and trades are verified before it is listed, and placement is never paid.
Questions people ask
Is the fan noisy?
The fan sits outside the living space, on the exterior or in the attic, so most homeowners hear little. A faint hum near the fan is normal.
How do I know the system is working?
The gauge on the pipe shows suction while the fan runs, and periodic retesting confirms the level in the house.
Does it work with a crawlspace?
Yes. A sealed plastic membrane is laid over the crawlspace floor and the suction pipe draws from beneath it.
Related: Radon testing · Crawlspace encapsulation · Sump pump installation · All inspections and testing
This page describes what the service involves. The company you hire sets the scope, the schedule and the price, and your contract is with that company. We verify credentials and collect reviews from real jobs. We do not guarantee any company's workmanship. Safety steps are general guidance. When in doubt, leave the home and call 911.