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Verified Reviews for Radon Detection And Reduction pros in Sisters, OR

*The Angi rating for Radon Detection And Reduction companies in Sisters, OR is a rating based on verified reviews from our community of homeowners who have used these pros to meet their Radon Detection And Reduction needs.

*The HomeAdvisor rating for Radon Detection And Reduction companies in Sisters, OR is a rating based on verified reviews from our community of homeowners who have used these pros to meet their Radon Detection And Reduction needs.

Last update on October 28, 2025

Find Radon detection and reduction specialists in Sisters

Avatar for TerraFirma Foundation Systems

TerraFirma Foundation Systems

7700 N Old Highway 99
5.00(
7
)

TerraFirma Foundation Systems

7700 N Old Highway 99
5.00(
7
)
Customers say: Quick response
Recommended by 100% of Angi customers
Recommended by 100% of HomeAdvisor customers

Thousands of NW homeowners have trusted TerraFirma Foundation Systems to keep their homes safe, dry and stable since 2005. Nearly half of our business comes from referrals or repeat customers. We can help you too! TerraFirma is the NW expert in home foundations, basement and crawl space waterproofing, concrete leveling, and wall stabilization.

"They were great. They had a great communication. They exceeded our expectations."

Rachel K on February 2021

Thousands of NW homeowners have trusted TerraFirma Foundation Systems to keep their homes safe, dry and stable since 2005. Nearly half of our business comes from referrals or repeat customers. We can help you too! TerraFirma is the NW expert in home foundations, basement and crawl space waterproofing, concrete leveling, and wall stabilization.

"They were great. They had a great communication. They exceeded our expectations."

Rachel K on February 2021

Avatar for Structure Building Solutions

Structure Building Solutions

5.00(
1
)

Structure Building Solutions

5.00(
1
)
Recommended by 100% of Angi customers
Recommended by 100% of HomeAdvisor customers

The Structure Process focuses on getting the job done with as little homeowner inconvenience as possible. Our 14 years of construction experience has focused on weatherization, defect repair, HOA maintenance, remodeling and new construction. Many people can claim quality and speed, but few have the same specialized background to back it up. Complex or small, there is no job we can't take on. We can accept credit, check or cash payments. $50 referral program.

The Structure Process focuses on getting the job done with as little homeowner inconvenience as possible. Our 14 years of construction experience has focused on weatherization, defect repair, HOA maintenance, remodeling and new construction. Many people can claim quality and speed, but few have the same specialized background to back it up. Complex or small, there is no job we can't take on. We can accept credit, check or cash payments. $50 referral program.

Avatar for John's Waterproofing

John's Waterproofing

219 Airport Rd
4.30(
240
)

John's Waterproofing

219 Airport Rd
4.30(
240
)
Customers say: Super punctual
27 local quotes requested

Since 1974, John's Waterproofing has been helping the PNW have dry and healthy homes. We specialize in below-grade waterproofing for crawlspaces and basements. In addition to this we also provide radon testing and mitigation, and humidity and mold control. We are proud to offer the best in the industry solutions to your homes waterproofing needs. Cost is determined by the job. CCB#15830 (503) 873-5650 [email protected]

"Chris and Joel were great, they were in and out and our water heater was rewired and sump pump wired in no time at all."

Dawn S on May 2025

Since 1974, John's Waterproofing has been helping the PNW have dry and healthy homes. We specialize in below-grade waterproofing for crawlspaces and basements. In addition to this we also provide radon testing and mitigation, and humidity and mold control. We are proud to offer the best in the industry solutions to your homes waterproofing needs. Cost is determined by the job. CCB#15830 (503) 873-5650 [email protected]

"Chris and Joel were great, they were in and out and our water heater was rewired and sump pump wired in no time at all."

Dawn S on May 2025

Cascade Radon Inc

12839 NE Airport Way
4.94(
157
)

Cascade Radon Inc

12839 NE Airport Way
4.94(
157
)
Customers say: Super punctual
Recommended by 99% of Angi customers
Recommended by 99% of HomeAdvisor customers

The Northwest's most experienced firm. Residential and commercial radon testing, mitigation, and system design for homes, schools, businesses. Radon-resistant design for new homes. We have been EPA-certified for over 25 years. Award winning. Radon is not a secondary endeavor for us… it’s all we do.

"Excellent from beginning to end. Very professional outfit from initial visit, quote, scheduling, work, followup. Price was reasonable, work quality went above and beyond, and radon levels dropped well below even the contractual level."

Claude S on April 2021

The Northwest's most experienced firm. Residential and commercial radon testing, mitigation, and system design for homes, schools, businesses. Radon-resistant design for new homes. We have been EPA-certified for over 25 years. Award winning. Radon is not a secondary endeavor for us… it’s all we do.

"Excellent from beginning to end. Very professional outfit from initial visit, quote, scheduling, work, followup. Price was reasonable, work quality went above and beyond, and radon levels dropped well below even the contractual level."

Claude S on April 2021

Avatar for Environmental Testing & Research Laboratories, Inc

Environmental Testing & Research Laboratories, Inc

60 Elm Hill Ave.
4.85(
347
)

Environmental Testing & Research Laboratories, Inc

60 Elm Hill Ave.
4.85(
347
)
Customers say: True professional
Recommended by 93% of Angi customers
Recommended by 93% of HomeAdvisor customers

ETR Laboratories in an analytic laboratory with a broad range of commercial, industrial and individual clients. We provide analytic services using a wide variety of scientific methods including GC/MS, IC/MS, GIR, NMR and SEM equipment. We can do particle analysis, organic and inorganic chemical analysis and micro analysis on biological and other materials. Private water analysis is our specialty. Award winning. Additional DBA - Environmental Testing & Research Laboratories Inc, ETR Labs, ETR Laboratories.

"as advertised"

Nancy C on July 2018

ETR Laboratories in an analytic laboratory with a broad range of commercial, industrial and individual clients. We provide analytic services using a wide variety of scientific methods including GC/MS, IC/MS, GIR, NMR and SEM equipment. We can do particle analysis, organic and inorganic chemical analysis and micro analysis on biological and other materials. Private water analysis is our specialty. Award winning. Additional DBA - Environmental Testing & Research Laboratories Inc, ETR Labs, ETR Laboratories.

"as advertised"

Nancy C on July 2018

Radon Detection and Reduction questions, answered by experts

Radon enters your home when warm air begins to rise and exits through the roof, creating a vacuum that pulls cooler air from under the foundation. Part of that air is radon, which is an invisible, odorless gas that develops naturally when radioactive particles are deep within the ground. Those particles usually come from decaying matter in soil and rocks.

Mitigation reduces radon levels, protecting your health and complying with safety standards.

Keeping radon from getting into your home is much better than having to get rid of it once it's already indoors. While there may not be a way to fully prevent radon from getting into your home, there are things you can do to reduce the gas's ability to enter. 

Sealing foundation cracks and openings can help keep the gas from seeping inside. Improving air flow, such as by opening windows, can also be helpful. If you're building your home from scratch, talk to your contractor about using radon-resistant construction to keep the gas out.

Testing every 2-5 years or upon adjusting occupancy or structural changes maintains safe environments.

Short-term tests take 2-7 days, while long-term monitoring may require up to 90 days for accurate results.

The Sisters, OR homeowners’ guide to radon detection and reduction services

From average costs to expert advice, get all the answers you need to get your job done.

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