Radon mitigation systems
A properly installed system usually brings radon well below the action level. Here's how they work and what to expect.
Most radon mitigation systems in Iowa homes use a method called sub-slab depressurization. Instead of filtering radon out of the air, it stops radon from getting in, by creating a slight vacuum under the floor and venting the gas outside before it enters the house.
How does a sub-slab system work?
- The installer drills a hole through the basement slab and digs out a small suction pit underneath.
- A PVC pipe runs from the pit, either through the house and attic or out through a rim joist and up the outside wall.
- An inline radon fan, mounted in the attic, garage or outside, runs continuously to pull soil gas through the pipe.
- The pipe vents above the roof line, away from windows and doors.
- Major cracks, the sump pit and other openings are sealed so the fan works efficiently.
- A pressure gauge (manometer) on the pipe shows the system is running.
What else might a system need?
- A sealed sump cover if the home has an open sump pit.
- More than one suction point if soil under the slab is tight or the house has separate foundation sections.
- A crawl space membrane for homes with crawl spaces. See crawl space radon.
Interior or exterior pipe?
Pipes routed inside, through a closet or utility chase up to the attic, are hidden and protected from the cold. Exterior routes are simpler to install but visible, and fans and pipes outside have to handle Iowa winters. A good installer will explain the options for your house.
How do I know it worked?
Test after the system is installed. Iowa's radon rules address testing before and after mitigation, including keeping the tester independent of the mitigation company. Ask the contractor how the post-mitigation test will be handled and what happens if levels are still high.
What affects the cost?
- Foundation type and size.
- Pipe route: interior through the attic or exterior.
- Number of suction points needed.
- Extras like sump covers, sealing or crawl space membranes.
Prices come from the radon company after they've looked at your home. We don't quote prices ourselves, and a phone estimate is only a starting point.
Where we connect you with help
Common questions
How much will a system lower my radon?
Results vary by house, but properly installed sub-slab systems commonly bring levels well below 4 pCi/L. A follow-up test confirms your result.
Does the fan run all the time?
Yes. Radon fans are designed to run continuously. Check the manometer now and then to make sure it's working.
Will a dehumidifier or air purifier fix radon?
No. They don't reliably lower radon. A mitigation system that stops radon at the foundation is the proven fix.
Related services
- Radon testing
- Crawl space and slab radon
- Radon for home buyers and sellers
- Radon system repair and checks
More background: Iowa radon guide.
Radon test came back high?
Call now and a local radon mitigation company will look at your home and quote a system.