Illinois Department of Nuclear Safety1 Radon Mitigation Overview So, you tell the homeowner that they have elevated radon. Now what do you tell them?

4/23/2015Illinois Department of Nuclear Safety 2 Homes With Radon Concerns Can Be Fixed! F Techniques have been developed to reliably reduce radon to less than 4.0 pCi/L. F Almost all systems can be installed in one day by a qualified contractor. F The repairs take 24 hours to take effect before retesting can occur F IDNS maintain lists of qualified contractors.

4/23/2015Illinois Department of Nuclear Safety 3 Radon Mitigation F Active Soil Depressurization (ASD) is the most common approach. –Employs a method for creating a vacuum beneath the foundation greater in strength than the vacuum applied to the soil by the building. F Caulking and Sealing is not a stand-alone technique. F Ventilation approaches have proven more costly and less effective.

4/23/2015Illinois Department of Nuclear Safety 4 Mitigation in Illinois F Must be effective at reducing radon F Must be unobtrusive and permanent F Must be quiet F Must be energy efficient F Must have a system function indicator F Primary suction point is independent of sump pit F Sump cover must have an observation port F Must exhaust above the highest eve of the roof. F Membrane must be adhered properly.

4/23/2015Illinois Department of Nuclear Safety 5 Crawl Space System Sub-Membrane Depressurization (SMD) n Vacuum applied beneath plastic. n Radon and moisture collected and exhausted above the highest eave.

4/23/2015Illinois Department of Nuclear Safety 6 Perforated Pipe on Soil n Perforated pipe used to collect gas n Laid on floor of crawl space

4/23/2015Illinois Department of Nuclear Safety 7 Plastic Spread Out in Crawl Space n High density polyethylene laid on dirt. n Edges and seams sealed.

4/23/2015Illinois Department of Nuclear Safety 8 Plastic Sealed to Wall with Caulk

4/23/2015Illinois Department of Nuclear Safety 9 Riser From Plastic n Perforated pipe connected to solid PVC pipe. n Sealed with 2 roof jacks sandwiched together. n Riser routed to fan.

4/23/2015Illinois Department of Nuclear Safety 10 Depressurization Fan n Installed in attic, garage, or outside the living envelope. n Quiet. n Less than 90 watts. n Expected life: 11 years.

4/23/2015Illinois Department of Nuclear Safety 11 System Discharge/Sub-slab depressurization n Discharge should be above highest eave and as close to roof ridge line as possible. n No rain cap. n 1/4 inch screen.

4/23/2015Illinois Department of Nuclear Safety 12 A System Performance Indicator Is Needed

4/23/2015Illinois Department of Nuclear Safety 13 Basement/Slab System Sub-Slab Depressurization (SSD)

4/23/2015Illinois Department of Nuclear Safety 14 Pipe Connected to Riser n Hole cut through slab. n Pit dug out. n PVC pipe connected to hole. n Pipe routed to suction fan. n Sump pit used only as a secondary suction point.

4/23/2015Illinois Department of Nuclear Safety 15 Caulking Improves Performance n Improves vacuum n Reduces loss of interior air n Polyurethane caulk n Not a stand-alone technique

4/23/2015Illinois Department of Nuclear Safety 16 Use of Perimeter Drain Drain-Tile Depressurization (DTD) n Very cost-effective n System completely outside n Care taken to avoid impacting water collection capability Floor Fan

4/23/2015Illinois Department of Nuclear Safety 17 Foundation Drain System Piping Can Be All Outside n Oversized downspout can be more attractive than pipe. n Outside. n Can be hidden.

4/23/2015Illinois Department of Nuclear Safety 18 NEW CONSTRUCTION F 1995 CABO - Radon control methods F Passive F Skeletal F Passive and skeletal are not acknowledged mitigation systems. F IDNS encourages homeowners to test their home to determine actual radon levels. F If homes are above 4pCi/l these systems should be converted to active soil depressurization by a IDNS mitigation professional.

4/23/2015Illinois Department of Nuclear Safety 19 Illinois New Construction Passive F Passive new construction systems rely solely on the convective flow of air upward in the vent pipe for sub-slab depressurization. The system consists of a vertical vent pipe routed through conditioned space from the suction pit to 12 inches above the roof.

4/23/2015Illinois Department of Nuclear Safety 20 Illinois New Construction Skeletal F A skeletal system is a system that is designed for the installation of a vent fan and may consist of multiple vent pipes. This includes vertical and angled runs that are not necessarily routed through living space that may be joined to a single termination above the roof or may terminated separately above the roof. EXHAUST

4/23/2015Illinois Department of Nuclear Safety 21 Key Elements of ASD Systems U.S. EPA Radon Mitigation Standards F Discharge points should be 10 feet above ground and 10 feet from any building opening that is on a plane 2 feet below exhaust. F Sealing concrete cracks, plastic in a sub-membrane, and open block tops; reduces operating costs, improves radon reduction, and minimizes potential for back draft of combustion appliances. F Proper system operation indicators and operation manual to be part of installation.

4/23/2015Illinois Department of Nuclear Safety 22 Radon Does Not Have To Be A Problem Nor A Deal Breaker For Sale SOLD