I understand that most radon mitigation systems are installed AFTER a house is built, but aren't there things that someone who is planning to "build" a home can do to minimize their risks for radon?
The best time to address radon is prior to construction when the majority of the home is accessible. Since 1997, Greenville County (SC) building code has required that contractors use "radon resistant construction techniques" on all new homes. This basically involves the placement of a 3-4 inch PVC pipe, (Schedule 40), down into 4-6 inches of gravel. Plastic sheeting is then put down and the foundation is poured onto the plastic securing the pipe's placement. The integrity of the slab should be maintained at all times. The pipe is routed up through the house (generally concealed in walls) and proceeds up through the attic to penetrate the roof. An electrical receptacle should be placed in the attic near the pipe (in case a fan is ever needed). The foundation is sealed and caulked thoroughly to prevent air leakage. If elevated levels of radon are encountered, a mitigation fan can be purchased and installed by a certified mitigator that will draw the radon gas up from under the foundation and vent it above the eaves of the roof. Be sure when framing to run the radon vent pipe from the basement of the highest part of the attic. This pipe should not be close to the attic eaves so that a radon fan may be easily added at a later date if needed.
I live in a county that doesn't have code requirements for installing radon piping in new homes. What should I do?
If the building codes in the county you reside do not address radon, you can contact us for information on "passive radon systems" which you can use to make sure that your builder incorporates into your house plans.
Should the builder test for radon after completion of the home?
There isn't currently a law in South Carolina that says that homes must be tested for radon prior to their sale. The decision to order follow-up testing for radon is generally left up to the homeowner. If initial testing indicates elevated levels of radon, a follow-up test is recommended to "confirm" the initial results. After the initial test, the best confirmatory type of radon test is a long term test using an "Alpha Track detector" (generally a 1-3 month test). The longer tests are not as subject to "fluctuation" and humidity as the short term tests are. If, at the completion of the long term test, elevated levels of radon are encountered, a mitigation fan can be ordered from a certified mitigation contractor to take care of the problem by either the builder or the homeowner depending upon the contractual agreements they have previously agreed on. The fan should be "installed" by a certified radon contractor. They will also install a "manometer gauge" on the pipe to measure air flow and indicates if the fan is producing the proper vacuum.
When is the best time to perform a radon test in a new home?
The ideal time to test a home is when you have plenty of time. You could test when the house is completed OR you could easily wait until you were "settled" and operating under normal living conditions.
The homeowner next door said his house had tested high for radon. Should I assume that the house I am building will have the same problem?
No! Each house and the "vacuum" in each house is different. The only way you can know if radon is a problem is to have your home tested by a certified test professional once it is complete. Don't rely on "assumptions" based on "misinformation!"
Who should perform the test?
There is more to testing a home for radon gas than deploying a couple of radon test kits. There are numerous things that can actually contribute to faulty radon test results. Only an individual trained in the proper EPA radon testing procedures should perform the test to ensure that the readings you receive are valid. Proficiency programs/exams for individuals in the radon test measurement and test interpretation field have been developed. Qualified professionals have received test measurement certification from either NEHA (National Environmental Health Association) or the NRSB (National Radon Safety Board).
What is a reasonable amount of radon?
The U.S. EPA and the U.S. Surgeon General's office have established that people should not be exposed to more than 4.0 pCi/L of radon on a long term basis. However, all levels of radon have anassociated risk factor.
For more information from the EPA on building your home with radon resistant construction techniques, click here