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Radon Environmental Issues for Real Estate Professionals. What Is Radon?. No. 1 cause of lung cancer among nonsmokers Second leading cause of lung cancer in the United States and Canada (next to cigarette smoke )
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What Is Radon? • No. 1 cause of lung cancer among nonsmokers • Second leading cause of lung cancer in the United States and Canada (next to cigarette smoke) • A smoker who is also exposed to radon has a much higher risk of developing lung cancer • Claims 21,000 lives each year
About Radon • A radioactive gas • Comes from the natural decay of uranium found in nearly all soils • Typically moves up through the soil to the air of your home through cracks and other holes in the foundation
Where Radon Comes From • Any home may have a radon problem • Radon can be found in any type of home, including new homes, old homes, well-sealed and drafty homes • Radon can be found in homes with basements, crawlspaces or slabs
Where Radon Comes From • Gaps around service pipes • Cavities inside walls • The water supply • Cracks in solid floors • Construction joints • Cracks in walls • Gaps in suspended floors
Radon • Test for radon during a real estate transaction • Fix the home if the radon level is 4 picoCuries per liter (pCi/L)or higher • Radon levels less than 4 pCi/L still pose a risk, and in many cases may be reduced Source: Zone and legend map provided by EPA Web site
About Radon • Even if built to be radon-resistant, every new home should be tested for radon as soon as possible after occupancy. • If you have a test result of 4 pCi/L or more, a radon fan can easily be added to a passive system to make it an active system and further reduce radon levels.
Radon Testing Ensure that the test is approved • EPA does not approve radon test devices • The National Environmental Health Association (NEHA) approves radon test devices • The National Radon Safety Board (NRSB) approves radon test devices
Testing Options: Passive Devices • Passive Devices • Charcoal canisters • Alpha-track detectors • Charcoal liquid scintillation • Available in hardware stores (plumbing department) • Generally requires at least 48 hours to complete
Radon Canisters • E-perm results can be calculated immediately upon retrieval of canister following the test period • E-perm uses electret ion chamber (EIC) technology
Testing Options: Active Devices • Active devices are the following: • Continuous radon monitors (CRMs) • Continuous working-level monitors • Require operation by trained testers • Provide a continuous report of radon levels present • Reveal unusual/abnormal swings in the levels during the test period • Designed to deter and detect test interference/tampering • More costly than a passive device • Ensure a more reliable result
Continuous Monitors • Instant results are available at the push of a button following the test period
Radon Mitigation A method using an active or inactive system to reduce radon levels in a home
Passive Mitigation • Gas permeable layer (stone) • Vapor barrier (prevents soil gas entry) • Sealed joints • 3- or 4-inch PVC pipe • Junction box for future fan in attic
Active Mitigation Active systems use a fan to direct the radon out of the home: • Sub-slab suction • Drain tile suction • Sub-membrane suction • Combination
Sub-slab Mitigation • Sometimes there is a lack of drain tile for sub-slab homes to tap into • In most modern construction, there is a drain tile under the slab that, when tapped into, can achieve good communication • The pipe is run up through the attic and through the roof or side wall (interior), or on the exterior of the home.
Sub-slab Mitigation Suction point in furnace closet in center of home All breaches need to be sealed (bathtub plumbing)
Drain Tile Mitigation • Installing a pipe through the slab to get to the drain tile can create good communication under the slab • Sump pits need to be sealed to prevent the home’s conditioned air from being sucked out of the home • Sump pits are also a good suction point to reach the drain tile
Sub-slab Mitigation Sealed pump with clear cover Suction point through slab
Drain Tile Mitigation Suction point from sealed sump pit
Sub-membrane Mitigation • Homes with crawl spaces with high radon levels require a 6-mm vapor barrier to be installed on the floor and sealed to the perimeter wall • All penetrations must be sealed through vapor barrier • A pipe is installed under the membrane and is the suction point
Combination • Suction points from basement and crawl spaces and/or slabs can be joined together to run to the outside
Pipe Termination • The pipe should terminate above the roof edge and not halfway up the side of the home to prevent concentrated radon levels from re-entrainment/re-entry back into the home • SHOULD NOT use gutter/downspout as exhaust pipe
Pipe Termination • SHOULD be above the eave of the roof • SHOULD be 10 feet or more above ground level • SHOULD be 10 feet or more from any window, door or other opening into conditioned spaces of the structure that are less than 2 feet below the exhaust point • SHOULD be 10 feet or more from any opening into an adjacent building
Pipe Termination Correct Incorrect —too short Incorrect —gutter
Fan Location • SHOULD be located on the outside of the home • SHOULD be located in an attic • SHOULD NOT be located in a basement or crawlspace • Electrical disconnect SHOULD be located where fan is and not in another room
Fan Location Incorrect — located in basement Correct — located outdoors
Fan Location Correct — located in attic
Special Items • Floor drains need sealing • Using a check valve, these floor drains can still be used • Fire collars are needed when a penetration occurs on the firewall, typically between the garage and the basement or crawl space