The reason most builders ignore the issue of radon contamination and indoor air quality is because it is not high on the agenda of most people in the construction industry.
- It is perceived that building with a higher indoor air quality standard is just an additional cost that would have to be put on the owner for something no one cares about.
- Most owners or buyers are not aware of the issue, and do not ask about it, and building departments in most states do not require a specific standard of indoor air quality in single-family homes.
- Most builders believe that the existing standard for air quality is good enough and that radon gas is not an issue to be concerned with.
Less fresh air leaks into today's tighter homes
This is a case of changing technology and consideration for a specific issue being out of sync.
In the not-so-distant past, most homes leaked so badly that the air inside would be exchanged on a regular basis with no help whatsoever. The leaking and changing of air in a home often contributed to venting radon gas, and bringing fresh air into the home, but not necessarily removing the gas to safer levels or creating better indoor air quality.
Today, with higher insulation levels and the use of housewraps that are properly installed, the leaking is much reduced.
- This sealing of homes has reduced that built-in air exchange, trapping more radon gas within homes, so additional systems must be incorporated.
- Most residential air conditioning/ heating systems are not designed to bring in fresh air, but recirculate the air within the building.
Conforming to EPA guidelines is easy
Combining a radon venting system and an air conditioning/heating system that brings in filtered fresh air is what is required to reduce or eliminate radon and improve indoor air quality.
Installation of the remediation system, regardless of the mechanical systems used, is relatively low-cost when compared to the cost of building a home or undertaking a major renovation.The truth is that the amount of work required to make a home conform to the EPA guidelines for radon remediation is very small, and not difficult.
With more people asking about green building techniques and air quality, many builders are responding and including the remediation systems in their projects.
More information about radon and its health impacts
Here is a breakdown of the information about the issue.Radon is:
- A naturally occurring gas formed by the decay of uranium that is found in nearly all soils.
- A known carcinogen as classified by the World Health Organization (WHO), the National Academy of Sciences, the U.S. Department of Health and Human Services, as well as EPA, because of its proven links to lung cancer in humans.
Health issues and exposure concerns:
- When a home or any other structure is built, radon is trapped within the structure after it enters the building through the basement, crawl space, or slab through holes or cracks or piping.
- The majority of structures have radon within them, but most levels are not above the maximum of 2 pCi/L (picocuries per liter of air) recommended by the EPA, and therefore no remediation is recommended.
- Levels between or above 2 and 4 pCi/L are recommended by the EPA to be remediated.
Remediation of radon:
- Remediation systems are similar if they are installed during construction or retrofitted. You must create a void either by installing gravel or a system of open piping below the slab, and install either a passive or mechanical vent to the exterior. All cracks and gaps must be sealed in the slab to ensure that radon is not seeping into the home.
- Many states require a licensed radon remediation contractor to design and install the system.
- In new construction, a system is installed to exhaust the gas from beneath the basement or main slab to the exterior, properly sized to keep the levels below the recommended level of 2 pCi/L.
- For an existing structure, testing must be performed to determine if remediation is required. A testing canister is placed within the structure for three days. The canister is then removed and tested in a laboratory to determine the level of radon within the structure. If the levels are determined to be too high, a licensed radon contractor can design a system to remediate the radon. A second three-day test must be performed after the installation of the venting equipment to determine if the levels are below the required maximum.
For more information:
Read "Why aren't more builders building homes with radon-resistant construction techniques? They fix radon and lower moisture!" a Q&A answered by Raymond Pruban.
Visit the EPA's radon website at http://www.epa.gov/radon/.