St. Louis Metro · Missouri & Illinois
Sub-Slab Depressurization Systems
Sub-slab depressurization is the system we install to bring a St. Louis home below the EPA action level of 4.0 pCi/L.
It draws soil gas from beneath the foundation slab and vents it above the roofline before it can enter the living space.
Most installations take a single day, and every one starts with a free in-home estimate.
The Target on Every Install
Systems are engineered to bring your home below the EPA action level of 4.0 pCi/L.
Built to performThe Method
How Sub-Slab Depressurization Works
Radon enters through the soil under your foundation.
A suction point is cut into the slab and connected to a sealed pipe. A fan pulls soil gas up the pipe and vents it above the roofline before it can enter the living space.
The system runs continuously and quietly once installed.
Install Day
What Installation Day Looks Like
- We confirm the suction point location and protect the work area
- The slab is cored and the pipe routed to the exterior or through the garage
- The fan is mounted outside the living space, per code
- Accessible entry points such as sump lids and slab cracks are sealed
- A manometer is mounted so you can verify suction at a glance
- We walk you through the system before we leave
Design
System Components and Placement
Pipe routing is decided with the look of the house in mind, not just the shortest path.
Fan sizing depends on how much resistance the soil under your slab presents. Undersized fans fail to pull enough; oversized fans waste energy and add noise.
Foundations
Foundation Types We Work With
- Full basements, finished and unfinished
- Slab-on-grade
- Crawl spaces, including encapsulated crawl spaces
- Mixed foundations where an addition changed the footprint
- Homes with existing sump pits
Afterward
After Installation
The system runs continuously from the day it is installed.
We recommend a follow-up radon test to confirm the level in your home once the system has been running. We can place a monitor for that test, or you can arrange it yourself.
Check the manometer a few times a year. If the fluid levels out, the fan needs attention.
Cost
What a Sub-Slab System Costs
Cost depends on foundation type, the number of suction points, and pipe routing.
We quote after seeing the house, so the number you get is for your home rather than a range off a website.
In the Field
Installed Systems
Get Your Number
Test came back high?
Free in-home estimate, custom-designed system, engineered below the EPA action level.