My basement had multiple cracks (no comments about my builder's skills). This product stopped leaks completely. Now I can install drywall. I bought the crack repair kit on Amazon, but I needed more co... See more
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A reasonable and helpful company. They answered questions, and assisted finding right product. The product isn't cheap, not expensive either, but works as it should. They provide plenty of documenta... See more
The customer service over the phone was amazing. The gentleman I talked to walked me through all the products I had questions on for 45min. He did not try to upsale me and even talked me out of one of... See more
Company replied
Fantastic product and support. Especially happy with Mike, who patiently answered my questions on multiple occasions and helped me find the right product for my project. The concrete sealant for my... See more
Company details
Written by the company
It happens to thousands of homeowners each year – the sale of their home falls through because of high radon in their basement. They have to hustle to get a radon mitigation system installed and hope that the buyer will not walk away. But for many years after, they may wonder about the long-term effects of the radioactive gas on their children. Since radon gas seeps into basements from the ground, the US Environment Protection Agency had tested the obvious solutions back in the 1980's – caulking all cracks and sealing the concrete with various coatings but the improvements were not significant or lasting. Thus, the fan-based system which draws soil gases from underneath basement slabs became the standard. There had to be a better way! Novion Inc. was founded in 1987 to pursue innovative high-tech solutions. Penetrating concrete sealers, already well-proven for waterproofing concrete on major projects, seal concrete internally and permanently. Perhaps, they could be improved to penetrate deeper and seal even tighter to keep out the single-atom radon gas. After extensive research and testing, the first concrete sealer specifically developed to reduce radon infiltration through concrete was ready for the big debut – RadonSeal® Deep-Penetrating Concrete Sealer. Novion Inc. was incorporated in Connecticut and RadonSeal was made available directly to homeowners and contractors on radonseal.com website. Subsequently, we have continued to add unique innovative products, not available in stores, for basements, indoor or outdoor concrete, bricks, pavers, and masonry. Going beyond radon remediation, we provide durable and cost-effective solutions for waterproofing basements, sealing concrete slabs against vapor, and mold remediation. Our products also protect and beautify indoor or outdoor concrete, pavers, and masonry. Our mission is to supply cutting-edge, professional-grade, and environment-friendly products, superior to those sold in stores. Our customer support offers technical expertise and objective guidance on the best solutions for customers' needs. Whether you are a homeowner, contractor, or building owner, we will provide the top-quality products and service to solve or prevent problems with your basement, parking lot, pool deck, brick or masonry walls. It can be just a matter of time before your basement or outdoor concrete starts giving you problems. Act now and give us a call. We are here to help!
Written by the company
Contact info
494 Bridgeport Ave, Ste 101336, 06484-4748, Shelton, United States
- 203 225-0366
- admin@radonseal.com
- radonseal.com
4.6
Excellent
2K reviews
Asks customers to review
This company invites their customers to review, whether positive or negative
Replied to 36% of negative reviews
Typically replies within 24 hours
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Easy to order
10 October 2025
Excellent product
ClayX worked like a charm. Needed a lot of elbow work, but most came off, some areas, all of it came off. I will be purchasing more to finish the small areas left.
18 September 2025
Shipment came in a timely manner and…
Shipment came in a timely manner and the application was very easy.
8 September 2025
Great products!
I have used RandonSeal products on several jobs. They are easy to use and get the job done correctly, the first time! I won’t use anything else!
7 October 2025
Product great
Product great
Arrived Fast
Coverage was as described, but I feel I needed several coats...my porch so porous that it drank it right up.
End result was just ok but only because I think I picked wrong color and need more coats
29 September 2025
The staff is great to help with any…product, shipping or anyother help you may need
The staff is great to help with any questions regarding ordering or helping with any product. They ship products well packed and in ship using great shipping company that you get your products very quickly.
26 September 2025
I have two calls in to you because it…
I have two calls in to you because it looks like my order has been canceled. It’s been two hours and no reply.
25 September 2025
Foundation Crack Repair and Concrete…
Foundation Crack Repair and Concrete Crack Repair kits work very well. Web site video showing how to use Foundation Crack Repair is excellent. Ordering and Checkout is straight forward.
22 September 2025
I had put off even starting my project
I had put off even starting my project, doubting I could do it well. I watched a really good you tube video (like around 8 times)about Radon Seal and how to do it from beginning to end. I finally ordered it, it came very quickly. And started it the next day. Finished it Saturday. Looks great!
Karen, age 68
5 September 2025
Super efficient process with updates along the way
The process was easy and smooth from order to getting tracking information. I ordered Sept 6th and my package started moving 9/9. I received an email update for every step. Very impressed. Also the tracking says to expect the product by 9/11. So 5 days in total from start to finish. Thank you!
8 September 2025
Top Notch
After waiting over 10 days for delivery from a second party, I reached out to RadonSeal directly. Customer support was very polite and professional and I received my order delivered to my doorstep within 2 days. You have a very happy customer that highly recommends RadonSeal.
5 September 2025
So far excellent store service and…
So far excellent store service and shipping. Get the product tomorrow
2 September 2025
Absolutely love the products
Absolutely love the products. Wish the shipping was a little faster, but I guess that’s on UPS.
2 September 2025
Great customer service.
27 August 2025
Your customer service person was great to work with
Your customer service person was responsive and helped me to understand which product and application method would work best for my issue.
27 August 2025
Customer service was very helpful and…
Customer service was very helpful and courteous. Product arrived as promised.
21 August 2025
I gave a 4 because of the ease I
I gave a 4 because of the ease I. Getting g started right away. I diagram of how to apply the epoxy to the knobs would have made my life easier. I also ran into an issue with the epoxy at the top and bottom of the wall. There should have been literature for both of these issues. There must be a complete seal in both locations in order for the system to work (continuous flow). You must assume that the people who are using this have zero knowledge. I would still use your product in the future. I just want it to work for all learners.
20 August 2025
Very good product kits for fixing…
Very good product kits for fixing cracks in basement walls or floors. Second purchase of repair kit. First one is now 6 years old and holding strong.
18 August 2025
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