How does mitigation work?
Active Soil Depressurization (ASD) is a fancy term for Radon Mitigation System.
A building creates negative pressure beneath itself that can force radon gas into the dwelling. What a mitigation system does is depressurizes the soil below the structure’s slab or vapor barrier by vigorously pulling air/gas from a suction point through a 3-4” PVC pipe, and expels it above the structure’s roof-line. This reduces the concentration of radon gas in the dwelling by pulling it through the pipe like a tunnel or a straw, and not allowing the gas to get trapped inside the structure.
This is achieved through the steps that follow:
1. A Radon Technician will seal all the cracks in the foundation that are accessible. This creates a more “air-tight” seal on the foundation slab for the system fan to pull from.
2. The suction hole is drilled into the foundation and a pit is excavated. This allows the system fan to pull air from under the slab of the structure.
3. Test holes are drilled in various slab locations. These small test holes allow the technician to verify that the fan is drawing suction from various locations in the slab.
4. A hole is drilled to run the piping to the exterior of the structure.
5. The fan is installed, and piping is routed above the roof-line, as per DEP guidelines.
6. After the system is activated, the technician verifies suction at test holes and a follow up radon test is administered.
This system is set up to provide a constant draw of gases from under the slab. These sub slab gases are pulled from under the slab and the radon fan extrudes these through piping above the roof line.