Types of Radon Mitigation Systems

Radon mitigation systems use soil depressurization to reduce radon levels inside a building. These systems come in several forms and are customized for each home or structure. Understanding the types of radon mitigation systems can help you choose the best approach to lower your radon levels.

Exterior Installed Radon Mitigation Systems

Exterior systems place the pressurized components outside the home. Interior sections operate under suction. The radon fan is usually installed at knee height on the exterior wall. From there, the vent pipe rises past the eave of the home.

 

Building code requires the vent opening to sit more than ten feet above the ground. It must also be at least ten feet from any window or door that is not at least two feet below the vent point. The vent pipe should rise vertically to release radon into the air and prevent it from reentering the home.

 

Exterior systems are easy to service and install, which makes them a common option.

Attic Installed Radon Mitigation Systems

Attic installed systems keep most of the system hidden from view. They also help protect the pipes and fan from freezing temperatures outdoors. In many homes, the system is routed through the garage and then into the attic above it.

 

If the garage route is not possible, the installer may use closets or utility chases to reach the attic. Building code requires the radon fan to be installed in a ventilated attic space or outside the home, never in a living area. This placement keeps the home safe from potential leaks.

Passive Radon Mitigation Systems

Radon resistant new construction techniques can be used to prevent radon gas entry in new construction homes or buildings. Most radon resistant designs consist of a gas permeable layer of gravel under the concrete slab, a soil gas collection pipe buried within the gravel layer, a suction pipe that extends through an interior wall and the exhaust point above the roof of the home. A correctly installed passive radon mitigation system should also include the sealing of cracks and sumps in the concrete slabs and foundation. The passive radon systems work by creating a vacuum through natural stack effect in the suction pipes and can be converted to active radon systems by installing a radon vent fan. 

Radon Mitigation for Crawl Spaces

Crawl spaces are common radon entry points. Radon can rise through floorboards and enter the living areas above the space. To prevent this, the crawl space should be sealed with a strong, airtight vapor barrier. Once sealed, a radon mitigation system can create suction under the membrane to remove soil gases.

How do radon mitigation systems work?

Radon mitigation systems operate through active soil depressurization. The system creates a vacuum in the soil beneath the foundation. This vacuum draws radon gas into the suction point, then through the vent pipe, and releases it above the roof.

Sub-slab Depressurization

A hole is drilled through the concrete slab to reach the soil below. Soil is removed to create a collection point. Suction pipes connect to this chamber and lead to the radon fan. This is the most common type of radon mitigation system.

Drain Tile Depressurization

This method uses the home’s existing drain tile or sump system. The system creates suction within the drain network, allowing radon to be pulled from a wide area around the foundation.

Sub-membrane Depressurization

In crawl spaces, a vapor barrier covers exposed soil. Suction pipes pull radon from beneath this membrane.

Block Wall Depressurization

In homes with block wall foundations, the system draws radon out of the hollow wall cavities.

 

Test your home, school or residential building for radon, our team can test radon levels and install a mitigation system to help protect against health risks associated with this toxic gas.