About Radon

Mitigation Systems










Active Soil Depressurization

Sub-Slab Depressurization (SSD)
SSD systems are the most common systems installed. SSD systems are used when a home’s foundation is a basement, crawlspace, or slab of concrete floor. The system works like this: the mitigation fan creates negative pressure below the concrete floor that draws the radon gas from the soil. Radon is then exhausted out and up through a PVC pipe, exiting above the roof. Pipe can be run through the home or outside of the home to the roof. See our Gallery of pictures.

Sub-Membrane Depressurization (SMD)
SMD systems are used when a home has exposed dirt or rock in a basement or crawlspace. A radon-retardant membrane (plastic sheeting) is permanently installed over the area that has exposed dirt or rock and sealed airtight. A PVC pipe penetrates the membrane and is run through the home and exits above the roof. A mitigation fan is installed to create negative pressure below the membrane to draw the radon out of the soil, into the pipe, and then exhausts the gas above the roof. See our Gallery of pictures.

99% of all radon mitigations use one or a combination of both of these systems. These are the preferred methods for Mock’s Radon Reduction, Inc. because it safely extracts radon away from the home.

Block-Wall Depressurization (BWD)
BWD is another active radon mitigation system that is not used as often as a SSD or SMD. The use of a BWD system is for homes with block wall foundations. Radon can travel through the inside of the blocks and into the house. A PVC pipe is installed into these walls in necessary locations. Suction is applied via a mitigation fan and routed through the home, exhausting above the roof. BWD is commonly used in conjunction with an SSD or SMD system because only removing radon from block walls will not lower radon levels as needed in most cases.

Passive Radon Reduction

Passive systems are very similar to active systems with the exception of not using a mitigation fan to produce negative pressure below the home. In most cases, passive radon systems are installed during new construction. All new homes should have a passive radon system, especially in our area.

A passive radon system includes a pipe fitted into the foundation prior to it being poured. This is done so that the passive piping will have good access to the radon air under the foundation floor. The pipes required for a radon system can be built into the home's interior walls with good maintenance access in the attic and then vented through the roof. There will be an area large enough to install a radon fan if radon levels are high upon home completion. An electrical outlet should be installed near the radon pipe in the attic.




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