The Biggest Problem with Radon-Resistant New Construction is… Don’t Forget to Do a Radon Test
By Arick Amspacker
What is Radon-Resistant New Home Construction?
Today’s new home buyer is much more aware of the health risks associated with indoor radon exposure. To meet this need, today’s savvy home builders are incorporating radon-resistant building techniques into their new home projects. Offering radon-resistant features can attract more potential buyers. More buyers means closing more sales and achieving higher profit margins on those sales. In fact, according to the National Association of Home Builders (NAHB), nearly one in 6 US homes are built using radon-resistant techniques. That’s currently about 200,000 homes a year.
The most common radon-resistant feature is called a passive sub-slab depressurization system (SSD). This technique can reduce radon levels by as much as 50%. An upgrade system is called an active sub-slab depressurization system and includes an in-line fan to provide even further indoor radon reduction. These systems are simple to install during construction and use common building materials. No special skills or materials are required, only knowledge of the proper installation techniques.
A radon-resistant new home is a good investment for both the buyer and the builder. It costs about $200 - $500 to install a passive SSD system during construction. Many builders have reported installation costs of less than $200 if they are already using some of the techniques for moisture control or energy efficiency. Compare that to retrofitting an existing home where the cost is typically $1000 - $2800.
You Still Need to Do a Radon Test
All new homes need to be radon tested after occupancy. This is true even if the home was built using radon-resistant features. If high radon levels are found, a passive SSD system can be upgraded to an active system by installing a centrifugal in-line fan. Typically a passive SSD system will have an electrical junction box installed in the attic to easily facilitate the fan installation. The new home owners need to be given written maintenance instructions for their SSD system. Some builders will also sell this upgrade as a way to control moisture in basements and crawlspaces. Controlling moisture is the key to reducing mold and mildew.
Which Radon Test Device Should We Use? A newly built home should be radon tested the same way any other home is tested. Radon testing is usually done in 2 phases. The first phase is called a screening test and the second phase is called a follow-up test. The radon screening test is a short-term test where the test devices are exposed between 2 and 90 days. I recommend builders provide the new home occupants with alpha track (AT) detectors. One AT detector should be placed on each livable level of the new home.
If you’re not sure how many AT detectors are needed or where they should be placed you may want to try the radon test wizard at www.homeradontest.com. This easy to use tool helps you choose the number and type of radon detectors needed for a particular home. The user is guided through the selection process by answering a few questions about the home to be tested.
The most important thing to remember is that you still must radon test a new home even though it has a passive SSD system installed.
