Radon reduction techniques are used to stop radon entry and reduce indoor radon
concentrations. There are different methods used, depending on the property configuration.
We utilize specialized equipment to discover where radon is entering the building and recommend the most effective radon mitigation system for the property.
The most effective measures for reducing radon, without costly renovations, are ones that limit soil gas entry into the building. In general, dangerous vapors are extracted from the soil and rock below the structure then exhausted, safely away from the building, prohibiting radon gas build-up.
One common and very reliable method uses Active Sub-slab Depressurization (SSD). This method uses a radon mitigation exhaust system to reduce the pressure below the floor slab so that the air between the building substructure and the soil flows out of rather than into the building. Sub-Slab Depressurizations systems are customized for each property, to address specific mitigation requirements.
A sub-slab depressurization system consists of PVC piping installed through the basement slab floor with a fan connected to the piping. When the system is on, the fan applies a vacuum beneath the slab and the vapors in the soil beneath the building are suctioned into the pipe, then exhausted. The primary suction provided is independent of the sump pit.
Radon is exhausted up through a PVC pipe that is positioned above the highest eave of the structure.
The exhausted radon gas is quickly diluted by outdoor air, rendering it harmless.
Exhaust outlets are installed as close to the roof ridge line as possible, 10 feet or more away from doors, windows or other openings in the building, and 10 feet or more from any openings in nearby structures.
In addition to the system functioning indicator we provide, we include a simple U-tube manometer
mounted to the Sub-slab depressurization system vent pipe. The manometer is widely used to monitor
the operation of the sub-slab depressurization system fan. When the liquid levels in the legs of the
manometer are uneven, a pressure differential exists, indicating correct operation of the fan and
system. Conversely, if the manometer liquid levels are even, the fan or system is not operating
properly and needs repair.
Sump pump covers are also installed with observation ports for performance monitoring.
A Sub-Membrane Depressurization (SMD) may be required for crawl spaces and other areas where the slab is in direct contact with the rock and soil. With the SMD method, a plastic sheet (Polyethylene or similar) is permanently installed over exposed rock and soil. A fan is then installed to create suction under the plastic sheeting, drawing the vapors out from the soil into a PVC pipe, then safely exhausted away from the home, minimizing vapors from entering the ambient indoor air, similar to the SSD method.
Both Sub-Slab & Sub-Membrane Depressurization systems must run continuously to be effective. These systems use little electricity, are relatively quiet, and require very little maintenance It is recommended that a professional inspect the system periodically to ensure proper performance.
Exhaust fans and piping are typically mounted on the exterior “equipment” side, of the building,
towards the back, in the most inconspicuous space. Optional fan housing units are available for
Exhaust piping is standard 3 inch PVC. Both the pipe and the fan housing may be painted to match the exterior of the home siding or trim. (Painting not included).
Typical installations include a Radon Away™ RP Series fan designed especially for radon mitigation, RadonAway’s RP Series fans provide superb performance and are ultra-quiet and attractive. They are ideal for most active sub-slab radon mitigation systems. Choice of model is dependent on building characteristics and should be made by a radon professional.
Sealing increases the overall effectiveness and cost efficiency of a mitigation system. Sealing cracks and gaps to limits airflow into the and out of the building enhances radon reduction efforts, by further blocking radon entry points and reducing the loss of costly conditioned air. IEMA does not recommend the use of sealing alone to reduce radon concentrations.
All systems installed by Professional Radon Systems, Inc., meet or exceed IEMA and EPA standards as well as Illinois building code requirements.