How to Test Radon in a Vacation or Second Home

Why Vacation Homes Are Higher Risk

Vacation homes have radon characteristics that differ from primary residences:

Long periods of sealed closure: A mountain cabin closed from October through May accumulates radon in a sealed environment with no ventilation. Levels during closure may be significantly higher than during active occupancy — and the structure retains elevated levels for hours after you arrive.

High-radon geography: Mountain cabins, lakefront properties, and rural retreats are disproportionately located in high-radon geological zones — the Colorado Rockies, the Appalachians, the Minnesota lakeshore. These are beautiful places to live, but uranium-rich geology underlies many of them.

Ground-level and basement sleeping: Vacation homes often have bedrooms in walk-out basements or ground-level rooms in contact with soil — the highest-radon spaces in any structure.

Testing Approach: Two Options

Option 1: Long-term test (if you use the property regularly)

Deploy a 90-day alpha track detector at the start of a season when you'll occupy the property for at least a few weeks of that period. The result reflects a mix of occupied and unoccupied conditions — a realistic picture of actual exposure.

This requires someone to retrieve the detector and mail it at the end of the 90-day period. If you're not at the property regularly, this is complicated.

Option 2: Short-term test during a stay

Arrive at the property; ventilate for 2–4 hours (open all windows and let it air out). Close everything up for 12 hours. Deploy the short-term test kit. Run for 48–96 hours under closed-house conditions. Mail immediately at the end of the stay.

This gives you a result reflecting the closed-house conditions of your typical stay — useful for making a mitigation decision.

What to Do With the Result

Below 2.0 pCi/L: Low risk. Retest every 2 years.

2.0–4.0 pCi/L: Moderate. Mitigation is optional but worth considering if you use the property extensively. Ventilate on arrival.

Above 4.0 pCi/L: Mitigate. The same sub-slab depressurization systems used in primary homes work in vacation properties. The challenge is contractor access if the property is remote — plan ahead, as some rural areas have limited contractor availability.

Remote and Rural Properties

If the vacation home is in a rural area with limited contractor availability:

• Search NRPP's national contractor directory by zip code
• Consider contractors from the nearest metro who travel to rural areas
• Some contractors in high-radon resort areas (Summit County CO, the Poconos, Lake Minnetonka area) specifically serve vacation home markets

Remote properties may also have limited electrical access for the fan — a battery backup or solar power source may be needed if the property doesn't have full-time electrical service.

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