Radon mitigation, also called radon remediation, is the process of reducing radon concentrations inside a building. Radon is a naturally occurring radioactive gas that can enter through foundation cracks, joints, and openings around pipes.
Common mitigation systems collect radon-containing soil gas beneath the building and carry it outdoors through vent piping, helping prevent it from entering occupied rooms. How the gas moves through that piping depends on whether the system is active or passive.
Types of Radon Mitigation Systems
Active and passive systems can collect gas beneath concrete floors or sealed membranes. The main difference is whether they use a powered fan.
Active Systems
An active radon mitigation system uses a continuously running fan to create suction beneath a concrete slab or membrane. This lowers air pressure relative to the building’s interior, helping direct soil gas into vent piping and outdoors.
Common active methods include:
-
Active sub-slab depressurization:
Collects gas through one or more suction points beneath a concrete floor. It is commonly used in buildings with basements or slab-on-grade foundations.
-
Sump suction:
Uses a suitable sump pit as the collection point. An airtight cover and vent connection allow gas collection while preserving the sump’s drainage function.
-
Active sub-membrane depressurization:
Collects gas beneath a sealed membrane covering exposed soil, typically in a crawlspace.
Some buildings, like those with both a basement and an exposed-earth crawlspace, need a combination of radon mitigation systems.
Passive Systems
A passive radon mitigation system relies on natural pressure and temperature differences to move soil gas through vent piping without a powered fan.
Passive configurations include:
-
Passive sub-slab systems:
Collect gas beneath a concrete floor and route it through a vent pipe. These systems are often incorporated into radon-resistant new construction.
-
Passive sub-membrane systems:
Collect gas beneath a sealed membrane covering exposed soil and route it outdoors through passive vent piping.
Passive sub-slab systems are generally less effective at reducing high radon concentrations than active sub-slab systems. If testing shows elevated levels, a qualified professional can evaluate whether adding a fan and making other adjustments will provide sufficient reduction.
How Is the Right Radon Mitigation System Selected?
A qualified contractor evaluates the building’s radon test results, foundation layout, and how easily air moves beneath the slab or membrane. Those findings help determine the collection points, piping route, and whether powered suction is needed.
Buildings with separate foundation areas may require multiple collection points or a combination of methods. The design should address the entire affected area, with follow-up testing used to confirm the result.
Discuss Radon Mitigation Needs With CABENO Environmental
CABENO Environmental provides radon and vapor mitigation services for commercial, industrial, and institutional properties. Whether you are addressing elevated radon in an existing building or planning a construction project, our team can help evaluate an approach suited to your property.
Explore our radon and vapor mitigation services, or contact CABENO Environmental to discuss the next steps.
