“Slab on grade”, “full basement”, “walkout basement”, and full or partially “crawl space” constructed homes may have high Radon Gas levels.
The goal of commonly installed Radon Gas reduction systems is to pull the Radon Gas from beneath the floor slab or crawl space before it rises into the home’s living areas.
The following are some examples of these reduction methods:
Create a hole to “pull” the Radon Gas from beneath the concrete floor of the lowest living or livable areas of the home. Pictures 1 & 2 are examples of an interior penetration and an interior penetration with a suction pipe attached.
If possible, an interior system may run from the basement floor penetration through a location in the home such as into a garage, closet or other accessible route to the attic. Picture 3 shows a suction pipe run through the “rim joist” into the garage. Picture 4 shows the pipe run through a main level closet.
With interior systems the fans are typically in the attic space, then vented trough the roof where a proper roof flashing is installed. See pictures 5 & 6 for examples.
Exterior systems are also an option, which may run from an interior floor penetration as shown in Pictures 1 & 2 or an exterior foundation penetration as shown in Picture 7. In these instances fans are installed at the homes exterior, see Pictures 8 & 9. The fan in Picture 9 may have a slight upgrade charge.
Earth floor crawl spaces, whenever possible are to be covered with 6mil Polyethylene plastic with a perforated pipe installed beneath connecting to one of the fore mentioned system types. The plastic vapor barrier has very specific sealing requirements to create an airtight membrane to pull the Radon Gas from the soil before it rises into the living area.
Other System Requirements
The vents exhaust termination point has very specific requirements for proper distances from the ground, all doors, windows, and other openings where the Radon Gas may reenter the home.
As per EPA/NRPP requirements, system-monitoring devices along with proper labeling are to be installed. See Picture 10 for the most common, reliable system function device (manometer tube).
A follow up retest of your Radon Gas levels is required per EPA standards.