*The Angi rating for Radon Detection And Reduction companies in Castro Valley, CA 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 Castro Valley, CA 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 May 31, 2026
Serving Castro Valley, CA and surrounding areas
Approved
In business since 1986
Free estimates
Customers say: Quick response
"Peter and his team at MG Remediation are professionals. They did everything they told me they would do and the radon levels dropped significantly. Great communication, too, which always matters."
+4
Serving Castro Valley, CA and surrounding areas
In business since 2000
Free estimates
Emergency services offered
"The person that came was fine. He just walked around and did the inspection. He also gave us some recommendations. The person was prompt, knowledgeable, and reasonably priced. He was very punctual."
Serving Castro Valley, CA and surrounding areas
In business since 1997
Free estimates
Emergency services offered
"The experience with Justin at Fire & Water Damage Recovery was excellent. They were referred by the plumbing company that serviced my sump pump. We still got 3 estimate, Justin's estimate was in the middle but I felt good with Justin based on our phone conversation and the referral so we went with this company. Justin did tell me that he might have estimated on the high side because he does not like to surprise the homeowners. What a surprise when I go the final invoice. The final invoice came in much lower and was very close or lower than the lowest estimate I got. Justin and his team also took pictures of how the place was before and after for me to see. They even took pictures of the pathway that they took to get to the crawl space to assure me that they kept the place clean when they got in and out. I was very satisified with Justin and his company."
+27
Serving Castro Valley, CA and surrounding areas
In business since 1991
Free estimates
Emergency services offered
"We needed to turn our home into a rental property. We had started to work with another contractor. Unfortunately, the contractor had our start date for a month after we needed the project completed. I searched Angie's List and found S&Y Corporation. They came to our house, within an hour after my first call and started the project the very next day.
S&Y Corporation is one of the most professional contractors that we have worked with. Their employees are skilled artisans. Our floors, walls and electrical work were a WOW, for us. I was so impressed with their service, that I wish we had found them sooner. I would hire them again, in a heart beat!. Mr. Young Ko takes pride in the work of his team and was good with follow up, before, during and after the projects. Great job! I will hire S&Y again."
Serving Castro Valley, CA and surrounding areas
In business since 2005
Free estimates
Credit card accepted
"Hector did respond to me and did fix the problem with the panels. Overall it was a good job."
+48
From average costs to expert advice, get all the answers you need to get your job done.
The cost of a radon mitigation system in San Francisco, CA, depends mostly on the type of system being installed. Use this guide to learn about your options.
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