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Radon Mitigation Systems: Condominium

 

Installing a radon mitigation system in a condominium can be more complex than in a single-family home due to shared walls, floors, ceilings, and building systems. However, it’s still very possible. Here’s how it can typically be approached, in accordance with EPA guidelines (Action Level: 4.0 pCi/L, usually for units up to the 3rd floor)

Step-by-Step Guide to Radon Mitigation in a Condo:

1. Test for Radon First

  • Ensure the unit has been tested properly.

  • Units on Ground Level and up to the 3rd floor are tested.

2. Check Building Ownership & HOA

  • Condos usually fall under a Homeowners Association (HOA) or shared ownership.

  • You will likely need HOA approval or building management involvement for:

    • Access to common areas (basements, roofs, walls).

    • External venting routes.

    • Electrical upgrades, if necessary.

3. Hire a Certified Radon Mitigator

  • Use a licensed or certified professional, listed through:

    • NRPP (National Radon Proficiency Program)

    • NRSB (National Radon Safety Board)

  • These pros will assess the unit and recommend the appropriate system.

Common Mitigation Methods for Condos

A. Active Soil Depressurization (ASD) – Most Effective

If your unit is on the ground floor:

  • A pipe is inserted through the slab or crawlspace to draw radon from beneath the building.

  • A fan (usually installed outside or in attic/common space) pulls the gas and vents it above the roofline.

  • Challenge: You may need permission to run piping through common areas or external walls.

B. Sub-Membrane Depressurization

  • Used if there’s a crawl space beneath your unit.

  • A heavy-duty plastic sheet is laid over the soil; vent piping and fan draw radon from underneath.

C. Sealing and Ventilation (Supplemental Only)

  • Sealing cracks and increasing ventilation can help, but they are not standalone solutions per EPA guidance.

D. Unit-Based Systems (If Ground Contact Is Indirect)

  • For second or thrid-floor units, mitigation might involve:

    • Checking radon pathways through plumbing or chases.

    • Sealing and local ventilation systems (like HRVs) to dilute indoor radon.

Special Considerations in Condos:

  • Shared Walls & Ceilings: You may be affected by radon entering from lower units.

  • Pressure Differentials: HVAC systems and elevator shafts can affect radon movement.

  • Stack Effect: In taller buildings, radon can rise, particularly in winter.