What to Do If Your Radon Levels Are High
So you tested your home and it's not looking great. Your result came back above 4 pCi/L. First, don't panic. Elevated radon is completely normal and totally fixable. We'll walk through everything you can do, step by step. And if none of it feels manageable on your own, the contractors in your area would genuinely love to help.
Start your confirmation test right now
Before you do anything else, get that second test going. Don't overthink it, don't wait until you've read everything on this page. Just open the long-term kit, place it, and start the clock. You'll be glad you didn't waste two weeks thinking about it.
If your short-term result is between 4 and 8 pCi/L, a 90-day long-term test gives you a number that reflects your actual annual average. A single short-term reading at 5 pCi/L could be a seasonal high. The long-term test tells you what you're actually living with. If it confirms elevated levels, you act. If it comes back below 4, your short-term test caught a temporary spike and you're fine.
If your short-term result is above 8 pCi/L, skip the confirmation test. That level is high enough to act on regardless. Go straight to Step 2.
Run the long-term test in the same spot as your short-term test for the most useful comparison.
Find a certified mitigation contractor
Do not hire just anyone. Radon mitigation requires a contractor certified by either the NRPP (National Radon Proficiency Program) or NRSB (National Radon Safety Board). These are the two EPA-recognized certification bodies. A certified contractor has passed exams, completed training, and follows established protocols. An uncertified one is guessing.
Ask any contractor you contact for their certification number. A legitimate pro will give it to you without hesitation. You can verify NRPP credentials at nrpp.info and NRSB credentials at nrsb.org.
Get at least two quotes. A typical sub-slab depressurization system costs $800 to $2,000 depending on your home size, foundation type, and local labor rates. If one quote is dramatically lower than others, ask what is different about their approach.
Use RadonLookup's contractor directory to find certified pros in your area.
Understand what the fix looks like
The standard solution for most homes is sub-slab depressurization. Here is what that means in plain English.
A contractor drills one or more holes through your foundation floor, inserts a pipe, and connects it to a fan. The fan creates negative pressure beneath your slab, drawing radon out from under the foundation and venting it outside through a pipe that exits through the roof or side of the house. Radon that would have seeped up through cracks and joints gets routed outside instead.
The system runs continuously. It uses roughly as much electricity as a light bulb. It does not require significant changes to your home and is not visible from outside in most installations. Most homes with elevated radon see levels drop to below 2 pCi/L after installation.
For homes with crawl spaces, the fix typically involves sealing the crawl space floor with a heavy plastic barrier and venting beneath it. For homes with block foundation walls, additional steps may be needed to address air movement through the blocks.
Your contractor should walk you through the specific approach for your home before any work begins.
Get a post-installation test
Any reputable contractor will perform a radon test after installing the system to confirm it is working. If a contractor does not offer this, ask for it explicitly. It is a standard part of the job.
The post-installation test should show levels well below 4 pCi/L, and ideally below 2 pCi/L. If levels are still elevated after installation, the contractor needs to adjust the system. This is uncommon with a properly designed installation but it does happen, particularly in homes with complex foundation configurations.
Get the post-installation test result in writing.
Keep your test results and installation paperwork. You will want them if you ever sell your home.
Test again annually
A mitigation system is not a one-time fix and forget. Fans can slow down or fail. Soil conditions change. Test your home annually after mitigation to confirm the system is still performing.
An annual short-term test costs $15 and takes 48 hours. It is the easiest part of the whole process. If a future test shows levels creeping back up, check whether the fan is running and contact your contractor.
Test at the same time each year so you are comparing like seasons to like seasons.
A note on rental properties and landlords
If you rent your home, the process is different. You cannot install a mitigation system yourself. That is the landlord's responsibility.
Start by documenting your test result in writing and notifying your landlord formally. Many states have radon disclosure laws and some have requirements for landlords to remediate. Check your state's regulations on the RadonLookup state page for your area.
If your landlord is unresponsive, your state health department or radon office can provide guidance on next steps.