Zone 1 areas have predicted average radon levels at or above the EPA's 4.0 pico-Curies per liter (pCi/L) action level. (pCi/L is a measure of the amount of radioactivity in a known quantity of air.) If you are building in a Zone 1 county, you should include a radon control system in your new home. It is an inexpensive addition to the total cost of your house and is an easy way to protect you and your family.
• To determine which radon zone your new house will be built, please contact your state
Talk to Your Builder
You and your builder can design your new house to be radon resistant. For a small fee your builder can take the following four simple steps to deter radon from entering your home.
• Install a layer of clean gravel or aggregate beneath the slab or flooring system.
• Lay polyethylene sheeting on top of the gravel layer.
• Include a gas-tight venting pipe from the gravel level through the building to the roof.
• Seal and caulk the foundation thoroughly.
These construction techniques will be familiar to your builder. There is no need to hire a special contractor or architect. Many builders already incorporate some of these steps in the construction of their houses to control moisture or increase energy efficiency. In fact, radon-resistant construction techniques can be found in the 1995 version of the One-and-Two Family Dwelling Code published by the Council of American Building Officials.
• Radon-Resistant Construction Techniques
Understanding a Radon System
Radon-resistant construction techniques comprise a "passive" radon system. This system overcomes the vacuum effect experienced by most houses by creating a pressure barrier to radon entry. The system also includes a pipe to vent radon gas safely to the outdoors.
Sometimes a passive radon system isn't enough to prevent radon from entering a house. In this case, a fan can be installed to pull the radon gas from the underlying soil into the vent pipe where it can be exhausted outside the house. The addition of a fan and its associated wiring creates and "active" radon system.
Testing: The Final Word
The only way to know if your new home has a radon problem is to test. The EPA recommends that average annual indoor radon levels do not exceed 4.0 pCi/L. If your home is built with a passive radon system, you should test it immediately after moving in to make sure that radon levels are below the EPA guideline. Remember: If your radon level is 4.0 pCi/L or above, a fan can be installed easily to lower radon levels well below this guideline.
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