Illinois Department of Nuclear Safety1 Radon Mitigation Overview So, you tell the homeowner that...

Illinois Department of Nuclear Safety 1

Radon Mitigation Overview

So, you tell the homeowner that they have elevated radon.

Now what do you tell them?

04/18/23 Illinois Department of Nuclear Safety 2

Homes With Radon Concerns Can Be Fixed!

Techniques have been developed to reliably reduce radon to less than 4.0 pCi/L.

Almost all systems can be installed in one day by a qualified contractor.

The repairs take 24 hours to take effect before retesting can occur

IDNS maintain lists of qualified contractors.


Radon Mitigation

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.

Caulking and Sealing is not a stand-alone technique.

Ventilation approaches have proven more costly and less effective.


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


Crawl Space System Sub-Membrane Depressurization (SMD)

Vacuum applied Vacuum applied beneath plastic.beneath plastic.

Radon and Radon and moisture collected moisture collected and exhausted and exhausted above the highest above the highest eave. eave.


Perforated Pipe on Soil

Perforated Perforated pipe used to pipe used to collect gascollect gas

Laid on floor Laid on floor of crawl spaceof crawl space


Plastic Spread Out in Crawl Space

High density High density polyethylene polyethylene laid on dirt.laid on dirt.

Edges and Edges and seams sealed.seams sealed.


Plastic Sealed to Wall with Caulk


Riser From Plastic

Perforated pipe Perforated pipe connected to solid PVC connected to solid PVC pipe.pipe.

Sealed with 2 roof jacks Sealed with 2 roof jacks sandwiched together.sandwiched together.

Riser routed to fan.Riser routed to fan.


Depressurization Fan

Installed in attic, Installed in attic, garage, or outside garage, or outside the living envelope.the living envelope.

Quiet.Quiet. Less than 90 watts.Less than 90 watts. Expected life: 11 Expected life: 11

years.years.


System Discharge/Sub-slab depressurization

Discharge should Discharge should be above highest be above highest eave and as close to eave and as close to roof ridge line as roof ridge line as possible. possible.

No rain cap.No rain cap. 1/4 inch screen.1/4 inch screen.


A System Performance Indicator Is Needed


Basement/Slab SystemSub-Slab Depressurization (SSD)


Pipe Connected to Riser

Hole cut through slab.Hole cut through slab. Pit dug out.Pit dug out. PVC pipe connected to PVC pipe connected to

hole.hole. Pipe routed to suction fan.Pipe routed to suction fan. Sump pit used only as a Sump pit used only as a

secondary suction point.secondary suction point.


Caulking Improves Performance

Improves vacuumImproves vacuum Reduces loss of Reduces loss of

interior airinterior air Polyurethane caulkPolyurethane caulk Not a stand-alone Not a stand-alone

techniquetechnique


Use of Perimeter Drain Drain-Tile Depressurization (DTD)

Very cost-effectiveVery cost-effective System completely System completely

outsideoutside Care taken to avoid Care taken to avoid

impacting water impacting water collection capabilitycollection capability

Floor Fan


Foundation Drain System Piping Can Be All Outside

Oversized downspout can Oversized downspout can be more attractive than be more attractive than pipe.pipe.

Outside.Outside. Can be hidden.Can be hidden.


NEW CONSTRUCTION

1995 CABO - Radon control methods

Passive Skeletal

Passive and skeletal are not acknowledged mitigation systems.

IDNS encourages homeowners to test their home to determine actual radon levels.

If homes are above 4pCi/l these systems should be converted to active soil depressurization by a IDNS mitigation professional.


Illinois New ConstructionPassive

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 .


Illinois New ConstructionSkeletal

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


Key Elements of ASD SystemsU.S. EPA Radon Mitigation Standards

Discharge points should be 10 feet above ground and 10 feet from any building opening that is on a plane 2 feet below exhaust.

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.

Proper system operation indicators and operation manual to be part of installation.


Radon Does Not Have To Be A Problem Nor A Deal Breaker

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Illinois Department of Nuclear Safety1 Radon Mitigation Overview So, you tell the homeowner that...

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