If you are one of the many homeowners taking steps to protect your family from radon gas, it is vital to ensure your mitigation system is installed correctly. The Environmental Protection Agency (EPA) developed the Radon Mitigation Standards (RMS) to provide a uniform set of requirements that ensure systems are both durable and effective at reducing indoor radon levels.

Here are the key standards every homeowner should look for when hiring a contractor or inspecting their own system.

1. A Permanent, Integrated Design

A radon mitigation system is not a temporary fix; it must be designed and installed as a permanent, integral addition to the building. The system should maximize radon reduction while being designed to minimize energy usage, limit noise, and avoid creating other health or safety hazards, such as backdrafting of existing combustion appliances.

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2. Proper Fan Location and Discharge

The placement of the radon fan is critical for safety. Radon fans must never be installed within the conditioned (heated or cooled) living space of a building, nor in basements or crawlspaces. Instead, they are typically located in attics, garages that are not beneath living spaces, or on the exterior of the house.

Furthermore, where the radon gas is released (the discharge point) is strictly regulated to prevent the gas from re-entering your home:

• The exhaust point should be above the highest eave of the roof whenever possible.
• It must be at least 10 feet above ground level.
• It must be at least 10 feet away from any window, door, or other opening that is not 2 feet below the exhaust point.

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3. Strict Electrical Requirements

As discussed in our previous conversation, electrical safety is a major focus of the RMS to prevent fire hazards and ensure the fan runs continuously. All wiring must conform to the National Electric Code (NEC). Specifically:

• No plugged cord may penetrate a wall or be concealed within a wall.
• Exterior fans must be hard-wired into an electrical circuit; the use of plugged fans outdoors is strictly forbidden.
• If a plugged cord is used indoors (for example, in an attic), it cannot exceed 6 feet in length.

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4. Sealing, Sump Pit Covers, and Membrane Integrity

For a radon mitigation system to pull gas effectively from the soil, the "suction" or vacuum must be maintained by meticulously sealing potential entry points. While sealing cracks in concrete slabs with durable materials like urethane is a standard requirement, specific attention must be paid to homes with crawlspaces or specialized foundation components.

• Soil-Gas Retarder Membranes: In crawlspaces, a continuous membrane—known as a soil-gas retarder—is laid over the earth to block gas entry. To ensure this barrier is effective, any seams in the membrane must be overlapped by at least 12 inches and should be sealed.
• Perimeter and Pier Sealing: The membrane cannot simply sit on the floor; it must be permanently sealed to the inside of exterior walls and around any interior piers to maintain an airtight seal. If wood is used to attach these membranes to walls or piers, it must be pressure-treated or naturally resistant to decay and termites.
• Material Standards: Not just any plastic sheeting will do. The standards require a minimum of 6 mil polyethylene(or 3 mil cross-laminated). If the crawlspace is used for storage or requires frequent entry for maintenance, a heavier gauge sheeting should be used to prevent tears.
• Penetrations and Sump Pits: Any openings where pipes or utilities penetrate the soil-gas retarder must be sealed in a permanent, airtight manner using compatible caulks or sealants. Sump pits used as suction points must be covered with a rigid, transparent lid that is sealed with a non-permanent material like silicone to allow for future servicing.

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5. Essential Monitoring and Labeling

You shouldn't have to guess if your system is working. Every active system must include a system failure warning device. This is often a liquid-filled tube called a manometer located on the vent pipe, which should be easily visible so you can verify the fan is creating the necessary suction. Additionally, the system must be clearly labeled with the installer’s contact information and a "Radon Reduction System" tag on every floor level where the pipe is visible.

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6. Post-Mitigation Testing

The job isn't finished until the air is tested. The contractor must conduct a post-mitigation radon test no sooner than 24 hours and no later than 30 days after the system is activated to ensure it is meeting the desired reduction goals. Once complete, they should provide you with a full documentation package, including maintenance instructions, any necessary building permits, and a description of how the system operates.

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If you've recently had a system installed and what a third-party assessment, give us a call!