- Building a New Home
- Have You Considered
Radon?
There are so many things to consider when
having a new home built - so many choices to make. How many bedrooms should you
have? Is the kitchen large enough? Do you need a basement?
You may even be concerned about
environmental issues, such as the fumes from new building materials and
furnishings. But are you concerned about radon? You should be.
What
You Should Know About Radon
Radon is a radioactive gas that comes
from the soil. Exposure to radon gas it the second-leading cause of lung
cancer (after smoking) in the United States. About 14,000 people die each year
from radon-related lung cancer.
Radon is produced from the natural
breakdown of the uranium found in most rocks and soils. As it further breaks
down, radon emits atomic particles. These particles are in the air we breathe.
Once inhaled, they can be deposited in our lungs. The energy associated with
these particles can alter cell DNA, thus increasing the risk of lung cancer.
Radon usually does not present a health
risk outdoors because it is diluted in the open air. Radon can, however, build
up to dangerous levels inside a house.
Radon
Entry
Radon can enter your new house through
cracks or openings in the foundation. The differences in air pressure between
the inside of a building and the soil around it also play an important role in
radon entry. If the air pressure of a house is greater than the soil beneath
it, radon will remain outside. However, if the air pressure of a house is
lower than the surrounding soil (which is usually the case), the house will
act as a vacuum, sucking radon gas inside.
Because radon comes from the soil, the
geology of an area can help to predict the potential for elevated indoor radon
levels. The U.S. Environmental Protection Agency (EPA) has worked with state
and federal geologists to develop maps which predict the potential indoor
radon levels for every county in the United States. Those counties with the
highest potential are designated as Zone 1; those with the lowest comprise
Zone 3.
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.) To determine which radon zone your new house will be built, please
contact your State radon office. 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.
Talk
to Your Builder
You and your builder can design your new
house to be radon resistant. For $350 to $500, on average, 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.
Understanding
a Radon System
The radon-resistant construction
techniques described in this brochure 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.
Even if you must install a fan, adding a
radon control system to a house under construction is much less expensive than
installing one after the house is built. The average cost for a radon control
system in an existing house is between $500 and $2,500. Adding radon-resistant
construction now will save you unnecessary expense and worry later.
For
Architectural Drawings and Technical Information
Detailed model building standards,
architectural drawings of radon systems, and fact sheets on alternative radon
installations are available from EPA at no charge by phoning 1-800-55-RADON
(1-800-557-2366).
Your builder can also obtain information
on radon-resistant construction techniques from the National Association of
Home Builders. Call the Home Builder
Bookstore at 1-800-223-2665 and order "Building Radon Resistant
Homes: A Builder's Independent Study Kit."
A growing number of municipalities
located in areas known to have high radon potential now require or recommend
that passive radon systems be installed in all new houses. Contact your State
Radon Office to determine if you are building your new home in such an area.
For
More Information
Many publications and
resources are available to you for free. Here are just a few suggestions:
- Home Buyers and Sellers Guide to Radon
- Consumer's Guide to Radon Reduction
- EPA's Map of Radon Zones
- Model Standards and Techniques for
Control of Radon in New Residential Buildings, developed by the U.S.
Environmental Protection Agency and the building industry with details on
how to install radon-resistant techniques in your new home.
- Architectural Drawings of
Radon-Resistant Construction Techniques
[You can also download a PDF version of the drawings: "Passive Radon
Control Systems for New Construction," EPA Document Number 402-95012,
May 1995. This PDF file includes (for one- and two-family dwellings): 1)
Passive radon control system; 2) Crawlspace radon control system; and, 3)
Additional fan for active system.]
- Other IAQ-related publications
Where To Find Free
Information
- National Service Center for
Environmental Publications (NSCEP)
http://www.epa.gov/ncepihom/
(to order EPA documents online)
Or call 1-800-490-9198/(513) 489-8695 (fax)
U.S. Environmental Protection Agency
National Center for Environmental Publications (NSCEP)
P.O. Box 42419
Cincinnati, OH 45242
Also Available
- The Council of American Building
Officials One- and Two-Family Dwelling Code Appendix F also details
radon-resistant techniques. Call (708) 799-2300.
To gain more information about building a
radon-resistant house or testing an existing home, please contact the Radon
Office in your State.
United States Environmental Protection
Agency
Indoor Environments Division
Office of Radiation and Indoor Air
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