Alabama Radon Education Program

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Alabama Radon Education Program
Building Radon Out Radon-Resistant New
Construction
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What is Radon?

• Radon is a radioactive gas
• Formed by natural decay of uranium, a common
  element present in soil and rock

• Radon is in the soil and air everywhere
• You cant see it, smell it, or taste it.
• Radon can be drawn into a building and accumulate
  to high levels.

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Is Radon a Health Risk?

• Radon is the second leading cause of lung cancer
  after cigarette smoking.
• Radon is a Class A carcinogen
• Radon causes 15,000 to 22,000 radon-related lung
  cancer deaths per year

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Is Radon a Health Risk?

• As exposure to Radon increases, so does risk for
  lung cancer.
• There is NO SAFE LEVEL -- even levels below 4
  pCi/l pose some risk

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How Does Radon Enter a House?

• Uranium is present in the soil nearly everywhere
  in the U.S.

• An air pressure difference between the basement
  or crawlspace and the surrounding soil draws
  radon into the house

• The soil is permeable enough to allow radon to
  migrate into the home through the slab, basement
  or crawlspace

• All homes have radon entry pathways -- such as
  the basement through small holes, cracks,
  plumbing penetrations, or sumps

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How Does Air Pressure Affect Radon Entry?

• Air pressure in a house is generally lower than
  in the surrounding soil, particularly in the
  basement and foundation levels.

• This difference in pressure causes a house to act
  like a vacuum, drawing air containing radon and
  other soil gases in through foundation cracks and
  other openings.

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Does Foundation Type Affect Radon Entry?

• Basement
• Radon can enter through floor-to-wall joints and
  control joints and cracks in the slab

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Does Foundation Type Affect Radon Entry?

• Crawlspace
• The vacuums that exist in a home are exerted on
  the crawlspaces causing radon and other gases to
  enter the home from the earthen area below.
• Even with crawlspace vents, a slight vacuum is
  still exerted on the crawlspace.

• Measurements in homes with crawlspaces have shown
  elevated radon levels.

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Does Foundation Type Affect Radon Entry?

• Slab-On-Grade
• Radon can enter a home regardless of whether or
  not there is a basement.
• Slabs built on grade can have just as many
  openings to allow radon to enter as do basements.

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Does Foundation Type Affect Radon Entry?

• Manufactured Homes
• Unless these buildings are set up on piers
  without any skirting placed around them, interior
  vacuums can cause radon to enter these types of
  homes as well.

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What Are Radon-Resistant Features?
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Would I Incur Liability by Installing
Radon-Resistant New Construction Features?

• Adopting radon-resistant building techniques
  should not increase your liability risks in any
  jurisdiction as long as due care is exercised in
  following the proper construction techniques
• In high radon areas, RRNC features may help you
  market and sell the homes you build.
• Code references listed in Building Radon Out

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What Code Do I Follow for Installing RRNC
Features?

• Once youve decided to build radon-resistant, you
  will want to make sure to install the features
  properly.
• There are building codes that apply to, or
  include, provisions for radon.

• Model Standards Techniques for Control of Radon
  in New Residential Buildings, 1994 EPA

International Residential Code, 2000-Appendix F
One Two Family Dwelling Code, 1995 CABO
Appendix F
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EPA recommends that all homes built in Zone 1
areas have radon reduction systems

• The NAHB recommends using the passive radon
  system in Zone 1 areas.

• This U.S. Geological Survey map, based on radon
  measurements, local geology and population
  densities, ranks all counties in the U.S. by
  zone. On a scale of 1 to 3, 1 has the highest
  risk for elevated levels of radon.

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Determine What Type of System To Install
Passive Sub-Membrane Depressurization System in
Crawlspace House

• It is cost-effective and recommended to install a
  complete passive sub-slab or sub-membrane
  depressurization system, which would be
  fully-functioning as soon as construction is
  finished.
• The home should be tested after occupancy, and
  the passive system should be activated if
  post-occupancy testing reveals radon levels at or
  above 4 pCi/l.

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Passive Sub-slab Depressurization System

• Gas permeable layer - 4inch layer of gravel used
  beneath slab
• Plastic sheeting - polyethylene sheeting placed
  on top of gas permeable layer to prevent soil gas
  entry
• Vent pipe - 3- or 4-inch PVC pipe runs from gas
  permeable layer, through house and roof
• Junction box - electrical junction box is wired
  in case fan is needed to activate the system
• Sealing caulking - all openings in concrete
  foundation floor are sealed to prevent soil gas
  entry

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Sold Working With Homebuyers

• 33 states in the U.S. have some form of
  regulation or legislation pertaining to radon.
• Most often that regulation pertains to real
  estate transactions.

• A basic passive radon system effectively reduces
  radon levels by an average of 50, in most cases
  below the action level of 4 pCi/l
• A RRNC home is a good investment because it is
  cheaper to install a passive system in
  construction (approx. cost 300-500) than to
  retrofit an active radon system (approx. cost
  1,500-3,000)

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Post Occupancy Testing

• After a home is complete and occupied, it should
  be tested to determine whether or not the passive
  system needs to be activated
• You should recommend to the homebuyer that they
  test the home after they move in and activate the
  system if the radon levels are at or above 4 pCi/L

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Activating the System

• Homes with a passive system can be upgraded to an
  active system with the simple installation of a
  special in-line fan to further reduce the radon
  level
• This upgrade can also be used by some to control
  moisture in basements and crawlspaces

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Activating the System
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What To Tell Homebuyers

• Let the homebuyer know that the only way of
  knowing if there are high levels of radon is to
  test
• A home with a passive radon system will reduce
  radon levels by 50 and significantly reduces the
  cost of dealing with high levels of radon at a
  later date
• The EPA strongly recommends taking action to
  reduce radon levels in a home that has a radon
  test result of 4 pCi/l or higher.

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Sold Working With Homebuyers

• RRNC features can also decrease moisture, soil
  gases, molds, mildews, methane, pesticide gases,
  volatile organic compounds, and other Indoor Air
  Quality problems

• Todays consumer is willing to pay more for a
  house that provides added protection for their
  family from indoor air quality environmental
  health concerns