HomeGuard Environmental WA
Verified Pro
3+ years online5.0(123)
Radon Mitigation in Seattle, WA
Compare 33 radon mitigation contractors near you in Seattle and surrounding area with an average rating of 4.9/5. Get free quotes, read reviews, and find the right pro for your project.
Last updated March 23, 2026
Most pros respond within 2–24 hours
Verified Pro Installers
Other Businesses in This Area
Green River Abatement
5.07+ years onlineIR Environmental
5.0~11 years onlinePNW Mold
5.0Radon Testing And Mitigation PNW
5.07+ years onlineR&M Asbestos Demolition
5.07+ years onlineService Pros & Asbestos
5.04½+ years onlineTotal Restore
5.02+ years online5 Microns Inc. Asbestos, Mold, Drinking Water, Radon, Air Quality Testing Lab
4.9Environix
4.923+ years onlinePillar To Post Home Inspectors - The Christensen Team
4.9Restoration 24
4.92½+ years onlineRobinson Restoration - Seattle
4.9~6 years onlineAdvanced Radon Technologies Inc
4.821½+ years onlineEnvironment Control North Seattle Restoration Services
4.821½+ years onlineFirst Response Water Damage Repair
4.817½+ years onlineSERVPRO of West Seattle and Burien
4.829 years onlineSERVPRO of Seattle NE
4.729 years onlineSERVPRO of Downtown Seattle
4.629 years onlineRadon Mitigation in Nearby WA Cities
Other Services in Seattle
Access Control & Intercom(33)Alarm System Installation(25)Appliance Installation(20)Artificial Turf Installation(27)Automotive Installs(1)Concrete & Paving(35)Deck & Patio Building(32)Electrical Services(24)EV Charger Installation(16)Fencing & Gate Installation(26)Fire Protection & Sprinklers(31)Garage Door Installation(23)
About Radon Mitigation in Seattle
Radon mitigation reduces radon gas levels in buildings, typically through sub-slab depressurization — a system that creates suction beneath the foundation to draw radon gas out before it enters living spaces. Radon is the second leading cause of lung cancer after smoking.
Typical costs: A standard sub-slab depressurization system runs $800–$2,500 installed. More complex situations (crawl spaces, multiple suction points) can be $2,000–$4,000. Radon testing before and after is typically included.
Common projects include:
- Sub-slab depressurization system
- Crawl space radon mitigation
- Radon testing and monitoring
- Sump pit sealing and venting
- New construction radon-resistant design
Many states require radon mitigation contractors to be specifically certified. Permits may be required for the system installation depending on jurisdiction.
Frequently Asked Questions
- How much does radon mitigation cost in Seattle?
- Most homes can be mitigated for $800–$2,500 with a sub-slab depressurization system. This includes the fan, PVC piping, sealing, and post-mitigation testing. The system runs continuously and costs about $50–$100/year in electricity. More complex jobs (crawl spaces, multiple foundation types) run $2,000–$4,000.
- How do I find a reliable radon mitigation contractor in Seattle?
- Use a certified radon mitigator (NRPP or state-certified). They should test before and after installation and guarantee results below 4 pCi/L (the EPA action level). Ask about fan warranty and what happens if the system doesn't achieve target levels.
- Do I need a permit for radon mitigation in Seattle?
- Requirements vary by state. Many states require radon contractors to be certified (not just licensed). Some require permits for the penetration through the foundation slab. Check your state's radon program for specific requirements.
About NeedInstall
NeedInstall helps connect customers with local installation professionals across Seattle and surrounding communities. Featured contractors have claimed their profile and verified their business information. Listings marked as "Verified Pro" have been confirmed by the business owner.