Radon
Radon Mitigation
There are several methods that can be used to lower radon levels in homes. Some techniques prevent radon from entering the home while others reduce radon levels after it has entered. EPA generally recommends methods that prevent radon entry. Soil suction, for example, prevents radon from entering the home by drawing the radon from below the house and venting it through a pipe, or pipes, to the air above the house.
The type of foundation a house has will affect the kind of reduction system that will work best.
Basement and Slab-on grade Houses
Active subslab suction (also called subslab depressurization) is the most common and usually the most reliable radon reduction method for basement and slab-on-grade foundations. Suction pipes are inserted through the floor slab into the crushed rock or soil underneath. They also may be inserted below the concrete slab from outside the house. The number and location of soil suction pipes that are needed depends on how easily air can move in the crushed rock or soil under the slab, and on the strength of the radon source. Acting like a vacuum cleaner, a fan connected to the pipes draws the radon gas from below the house and releases into the outdoor air. Drain tile suction, sump hole suction and block wall suction are other possible soil suction techniques.
Passive subslab suction is the same as active subslab suction except it relies on air currents instead of a fan to draw radon up from below the house. Passive subslab suction is generally not as effective in reducing high radon levels as active subslab suction.
Crawlspace Houses
In houses with crawlspaces, radon levels can sometimes be lowered by ventilating the crawl space, with or without the use of fans. Crawlspace ventilation lowers indoor radon levels both by reducing the home’s suction on the soil and by diluting the radon beneath the house. Installing additional vents may be necessary or opening existing vents may be sufficient. In cold weather the increased ventilation will necessitate the insulation of water pipes in the crawlspace.
Another effective method to reduce radon levels in crawlspace houses involves covering the earth floor with a heavy plastic sheet. The plastic needs to be sealed with caulking to the crawlspace walls, at seams, around support columns, and plumbing, drains or other penetrations. A vent pipe and fan are used to draw the radon from under the plastic and vent it to the outside. This form of soil suction is called submembrane depressurization.
Other Radon Reduction Methods
Other radon reduction techniques that can be used any type of house include: sealing, house pressurization, natural ventilation, and heat recovery ventilation. Most of these types are considered to be either temporary measures, or only partial solutions to be used in combination with other measures.
Costs
The cost of making repairs to reduce radon depends on how the home was built and the extent of the radon problem. Most homes can be be fixed for about the same cost as other common home repairs like painting or having a new water installed. The average house costs about $1200 for a contractor to fix, although this can range from about $500 to about $2500.
Certified Contractors
Use of certified contractors is recommended. Radon mitigation providers may be certified by the National Environmental Health Association (NEHA) or the National Radon Safety Board (NRSB).
Radon exhibits and/or presentations may be scheduled for appropriate groups or functions such as health fairs, farm and home safety fairs, consumer groups, etc.
Links
Mitigation of CRCPD Office Building
“Putting Your Money Where Your Radon Is”