Short-term
Useful for an initial screen when time matters. Duration depends on the device; follow its instructions.
Radon guidance for St. Augustine and St. Johns County
Your address needs a measurement—not a countywide guess.
Start with a properly run test, understand the result and verify any Florida radon business before deciding what comes next.
01Measure this building
Not a county average.
02Interpret carefully
Use current EPA guidance.
03Verify the provider
Confirm Florida certification.
The useful local answer
A map can describe potential. It cannot measure your rooms.
EPA built its county-zone map to help governments target resources—not to decide whether a particular home needs testing.
Building details, operation and test conditions can affect an indoor result. That is why the most defensible sequence is simple: measure first, then make the next decision from that result. EPA says to test regardless of zone and to fix at 4 pCi/L or higher.
Primary source: EPA Map of Radon Zones.
A sound measurement
Test conditions are part of the result.
The device belongs in the lowest level that could be used regularly, in a location that follows the device and testing protocol. For short-term testing, closed-house conditions generally mean windows closed, exterior doors used only for normal entry and exit, and no fans that bring outdoor air inside. Heating and cooling operate normally.
- Follow the device’s required exposure time and placement instructions.
- Record start and stop times and protect the device from interference.
- Do not treat one hourly rise as proof of a specific soil or weather cause.
Choose the path that fits the decision
Short-term, long-term and transaction testing answer different timing needs.
Long-term
More likely to represent a year-round average because it spans more of the building’s variation.
Real estate
Uses transaction-specific quality controls. EPA’s current guide calls for at least 48 hours, with some devices requiring longer.
Read the number without inventing a cliff
4 pCi/L is an action level—not a “safe” line.
EPA recommends fixing a home at 4 pCi/L or higher and considering reduction between 2 and 4 pCi/L. CDC says no radon level is known to be safe. A lower measurement means lower risk, not zero risk.
2.0–3.9pCi/L
Consider reducing. Review the result, test quality and available reduction options.
4.0+pCi/L
Take action. EPA recommends fixing the home. Use a qualified, Florida-certified business.
No band is labeled “safe.” Color is reinforced by text and numbers.
If a result is elevated
It is a building problem to solve—not a diagnosis.
An elevated measurement calls for a technical response. It does not determine any one person’s health outcome, identify the source of a short-term fluctuation or substitute for medical advice. If you have health concerns, speak with a qualified clinician.
- 1Confirm the test quality
Check duration, placement, conditions and device instructions.
- 2Follow current guidance
CDC advises a second test after a high short-term result.
- 3Verify the business
Florida certification must be current for paid measurement or mitigation work.
Mitigation, without sales promises
A proposal should respond to the building and the measurement.
Active soil depressurization is a common radon-reduction approach, but a responsible design depends on the foundation and diagnostic findings. Do not accept a universal promise about price, installation time, fan life, energy use or the final number.
Understand mitigationFour places a proposal should be specific
- MeasurementMethod, result and test conditions
- FoundationAssessment and suction-point design
- SystemFan, vent, electrical, sealing and discharge details
- CloseoutPost-mitigation testing, instructions and written warranty
Florida verification
Check the business—not just a person’s general trade credential.
Florida law regulates paid radon measurement and mitigation. Ask for the radon business certification number, confirm it against the current Florida Department of Health lists, and make sure the certified business named on the report or proposal is the one doing the work.
Florida real estate
The radon paragraph in a contract is a notice—not a property result.
Florida Statutes section 404.056 requires prescribed radon notice language on at least one document at or before a building sale contract or rental agreement, subject to a limited transient-occupancy exception. Its presence does not mean that the property was tested or that radon was found.
Use the transaction guideSeparate track
Schools, day cares and care facilities
Institutional requirements should not be inferred from homeowner guidance.
Florida’s current mandatory-testing page lists St. Johns County for covered facilities, with a building-type exception for structures coded as single-family housing or duplexes. Facility type, building use, testing history and triggering changes matter. Operators should check the current DOH page and facility database or contact the Radon Program rather than rely on a residential website for a compliance conclusion.
St. Augustine context
Use local agencies for local approvals—not a blanket permit claim.
A mitigation proposal may involve building, electrical or other regulated work. The correct authority depends on the property’s jurisdiction and scope. Ask the provider to identify required approvals in writing, then confirm with St. Johns County Building Services or the City of St. Augustine Planning and Building Department.
Official links: St. Johns County permits and City of St. Augustine permits.
Carefully qualified answers
Questions worth settling before you spend.
Can a county radon map tell me what my home will measure?
No. EPA says its Map of Radon Zones should not be used to decide whether an individual home needs testing. A map can support planning and outreach; a properly run test is what measures a building.
Is 4 pCi/L a safe-versus-unsafe boundary?
No. Four picocuries per liter is EPA’s action level, not a zero-risk line. EPA recommends fixing at 4 pCi/L or higher and considering reduction between 2 and 4 pCi/L. CDC says there is no known safe radon level.
How long does a radon test take?
Short-term devices remain in place from two to 90 days, depending on the device. Many time-sensitive real-estate measurements use a minimum 48-hour exposure, but the device instructions and applicable protocol control. Long-term tests run more than 90 days and better represent a year-round average.
Does Saint Augustine Radon Pros perform tests or install systems?
No. This is an independent informational and lead-introduction website, not a Florida-certified radon measurement or mitigation business. Verify any provider’s current Florida certification and written scope before hiring.
Project request
Start with the decision you need to make.
Share a small amount of project context for owner review. A phone number is optional. Do not include medical history, smoking status, payment details or other sensitive information.
What happens next
The site owner reviews the request and may reply by ordinary email. Details are not automatically shared with contractors.