Radon mitigation typically involves installing a fan system to vent gas from beneath the foundation to the outdoors, reducing radon levels inside the building.
If mitigation is needed, we recommend using a radon mitigation contractor certified by the National Radon Proficiency Program (NRPP). A complete list of NRPP contractors and their contact information can be found on the NRPP website.
More information on radon mitigation can also be found in the EPA's "Consumer Guide to Radon Reduction".
Selecting a Radon Mitigation Contractor
We suggest selecting a contractor to fix a radon problem just as you would choose someone to do other home repairs.
Look for certified contractors and ask for references who are satisfied with the contractors' work. A full list of radon measurement and mitigation contractors certified by the National Radon Proficiency Program (NRPP) can be found on the NRPP website.
Before beginning any radon mitigation work, you should review radon measurement results with the contractor.
Ask whether the contractor will be following ANSI/AARST standards.
Ask if the contractor charges for diagnostic testing, and discuss what diagnostic testing they may be recommending.
The contractor should be able to evaluate the radon problem and provide you with a detailed, written proposal on how radon levels will be lowered.
The contractor should also make sure the system effectively reduces radon to acceptable levels after it is in place and operating.
Be aware that a conflict of interest exists if the same person or firm performs the testing and installs the mitigation system.
As with other types of contractors, you may wish to get more than one quote. Compare the contractors' proposed costs and consider what you will get for your money. Take into account the following: a system that is less expensive to install may have higher operating and maintenance costs than a system that is more expensive to install; the best system for your house may be the more expensive option; and the quality of the building materials will impact how long the system lasts.
Do the contractors' proposals and estimates include:
- Proof of liability insurance, being bonded and licensed?
- Proof of NRPP or NRSB certification?
- Diagnostic testing prior to design and installation of a radon reduction system?
- Installation of a warning device to caution you if the radon reduction system is not working correctly?
- Testing after installation to make sure the radon reduction system works well?
- A guarantee to reduce radon levels to 4 pCi/L or below, and if so, for how long?
The Contract
Ask the contractor to prepare a contract before any work starts. Carefully read the contract before you sign it. Make sure everything in the contract matches the original proposal. The contract should describe exactly what work will be done prior to and during the installation of the system, what the system consists of and how the system will operate. Carefully consider optional additions to your contract that may add to the initial cost of the system, but may be worth the extra expense. Typical options might include a guarantee that the contractor will adjust or modify the system to reach the promised radon level, or, an extended warranty and/or a service plan.
The contract should also include:
- The total cost of the job, including all taxes and permit fees; how much, if any, is required for a deposit; and when payment is due in full.
- The time needed to complete the work.
- An agreement by the contractor to obtain necessary licenses and follow required building codes.
- A statement that the contractor carries liability insurance and is bonded and insured to protect you in case of injury to persons, or damage to property, while the work is being done.
- A guarantee that the contractor will be responsible for damage and clean up after the job.
- Details of warranties, guarantees or other optional features, including the acceptable resulting radon level.
- A declaration stating whether any warranties or guarantees are transferable if you sell your home.
- A description of what the contractor expects the homeowner to do (e.g., make the work area accessible) before work begins.
Home Buying & Selling
Buyers and sellers often test for radon during real estate transactions and the level of 4 pCi/L is commonly used to determine if mitigation is necessary. Though testing is a good idea for long-term health protection, there are no laws in Missouri that require this testing or that require mitigation by the seller. For more information consult the brochure "Home Buyer's and Seller's Guide to Radon."