• Can the contractor provide proof of certification and/or professional proficiency?
• Can the contractor provide proof of liability insurance?
• Will the contractor provide references or photographs, as well as test results of 'before' and 'after' radon levels of past radon mitigation work?
• Can the contractor explain what the work will involve, how long it will take to complete, and how the radon reduction system will work?
• Will the contractor perform diagnostic tests prior to design and installation of a radon reduction system?
• Does the contractor charge a fee for diagnostic tests?
• Will the contractor install a warning device to warn if the radon reduction system is not working correctly?
• Will the contractor test after installation to make sure the radon reduction system works well?
• Does the contractor guarantee to reduce radon levels to a specific acceptable level?

Before selecting a radon professional homeowners should always get estimates, ask questions, check references, and shop around.

WHY DO RADON PROFESSIONALS DO MORE TESTING
A radon professional will need to perform diagnostic tests pre- and post-mitigation to ensure a specific system design will be effective in the home. There may be an additional fee for these tests.