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Penetrating concrete sealers | Do-it-yourself basement waterproofing | Basement and concrete repairs
RadonSeal® Penetrating Concrete Sealer has been the most trusted and widely-used concrete sealer for both construction and residential waterproofing projects. RadonSeal® is a reactive, internal sealer for concrete, mortar, and other cementitious materials. It penetrates deep into concrete (up to 4 inches), reacts, expands inside the pores, and cures as a hard silicate mineral preventing the transmission of water seepage, water vapor, efflorescence, and even radon gas.
THE SEAL IS PERMANENT! Unlike common surface sealers (membrane coatings) or waterproofing paints sold in stores, RadonSeal will never peel off or wear away. There is no need to ever reapply the product again! Once RadonSeal has cured inside the concrete, it can not be pushed out regardless of hydrostatic pressure. The seal becomes integral to the concrete providing hardness and durability. Think of it like injecting more cement into the concrete!
The only sealer backed up by a Limited Lifetime Money-Back Guarantee
ECO-FRIENDLY – RadonSeal is a user- and environment-friendly waterborne sealer formulated for an easy and safe application. Non-hazardous, ZERO VOCs with no fumes or noxious odors.
Read Through Years Of Customer Success Stories
USE TO WATERPROOF CONCRETE WALLS AND FLOOR – RadonSeal is the heaviest available silicate-based sealer, which penetrates deeper, carries more active minerals, and seals tighter than any other concrete sealer. The penetration does not depend on gravity – it is also used on walls and ceilings. In case of basement walls, RadonSeal is normally applied to interior walls to seal against water seepage, water vapor, and radon gas from theground. However, if there is an opportunity to apply it to the outside, it has the added advantage of preserving the exterior of the concrete and extending the life of waterproofing coating.
USE AS A CONCRETE PRIMER – Because RadonSeal protects concrete against water vapor, efflorescence, and the "alakli attack" it is commonly used by flooring contractors as a concrete primer. RadonSeal is suitable for use before applying paints, adhesives, epoxy floor coatings, concrete overlays, surface levelers, membrane "wet-look" coatings and before the installation of moisture sensitive flooring.
USE TO AS A CONCRETE DENSIFIER – Once cured, RadonSeal makes concrete denser and stronger (up to 40% in flexural strength). Use on polished or non-polished concrete surfaces to reduce dusting, crumbling, and overall wear.
Use RadonSeal Standard for sealing poured concrete less than 20 years old, walls, floor, or poured outdoor concrete less than 2 years old. Use RadonSeal Plus (higher mineral content) for sealing older, more porous concrete; poured concrete older than 20 years, concrete blocks, cinder blocks, or poured outdoor concrete more than 2 years old. See coverage below.
How To Order: For secure and encrypted online processing of your order, click Order Online. All major credit cards accepted, or order with your PayPal account, or through Google Checkout. Or simply phone your order in. If you prefer mailing a money order or check, use the Order Form. RadonSeal is also available through Amazon.com. Available in Canada from ECO Buillding Resource, Ontario tel. 905-841-3535.
| RadonSeal Standard & RadonSeal Plus Concrete Sealer | |||||
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Item | Size | Price | Shipping | |
| RadonSeal Standard | 5-gals. | $149 $20 OFF (was $169) |
$15 |  |
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| 2.5-gals. | $89 | $12 | |
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| RadonSeal Plus | 5-gals. | $169 $20 OFF (was $189) |
$15 | |
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| 2.5-gals. | $99 | $12 | |
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Shipping: RadonSeal is not sold in stores. RadonSeal is shipped directly from the factory to your door (via UPS). Orders received by 3 pm ET are normally shipped the same day and UPS Ground delivers within 2 to 5 working days in the lower 48 states. Based on shipping by courier to the lower 48 states. For expedited shipping or shipping to other states (AK, HI) please inquire first by e-mail or telephone. Unopened pails in salable condition are returnable. Please review our Commercial Terms
Commercial Applicators: Available in 55-gallon drums at volume discounts or 24 and 36 pail shipping pallets. Please call or email us at Commercial Inquiries.
Unsure about your selection? Visit How To Select The Best Sealer For Your Project
The history of penetrating silicate concrete sealers dates back to Germany in World War II, when they were used to strengthen quickly poured thin military runways. After the war, the Army Corps of Engineers started using the sealers for the preservation of concrete dams and bridges. As the technology evolved, the use of silicate concrete sealers expanded from preserving structural concrete to waterproofing outdoor and indoor concrete. Somewhat diluted, they are also used as "surface hardeners."
During the last couple of decades, penetrating silicate concrete sealers have become widely used in the US and abroad, be it at Disney World or Sydney Opera House. Many architects specify them for major buildings. The sealers have been successfully used on thousands of major concrete structures and buildings.
How does RadonSeal work? When concrete cures, it produces "free lime" as a by-product. RadonSeal chemically reacts with the free lime inside concrete and expands inside the capillaries. It forms a silicate mineral – the same mineral produced by the hydration of cement paste, which bonds, strengthens, and seals the concrete. Sealing with RadonSeal is like injecting portland cement into the pores in concrete. Simply, it results in a higher grade of concrete that is denser, stronger, and tighter.
For more info on how RadonSeal works, the “alkali attack," efflorescence, how to protect concrete, paints, and flooring against deterioration, visit Sealing Concrete with RadonSeal
RadonSeal is not advised for use on fiber reinforced concrete, thin concrete floors (<2"), lightweight CMU's, splitface blocks, or "popcorn" blocks. It is most commonly applied to waterproof basements, foundation walls and floors, but also effective for sealing a wide range of cementicious materials (indoor or outdoor). Before purchasing, please take the time to review the RadonSeal Detailed Instruction & Sealing Various Cementitious Materials
COMMON RESIDENTIAL USE: basement floors, basement walls, garage floors, retaining walls, driveways, pools, walkways, koi ponds.
COMMON COMMERCIAL USE: parking garage, concrete facade, sidewalks, industrial flooring, concrete structures, warehouse floors, cooling towers, water treatment plants, bridges.
Need To Seal Brick? Use LastiSeal Brick & Masonry Sealer
The amount of coverage depends greatly on the porosity and composition of the concrete. Concretes with larger pores or more alkalis consume more sealer. Cinder blocks are very porous and have the lowest coverage. On average, a typical basement (floor 800-1,000 sq. ft./poured foundation) would require TWO (2) 5-gal. pails to seal both the basement floor and foundation walls.
Ideally, the concrete should be dry to start. Let concrete dry for 2 days after a heavy rain. Avoid heavy rain for 24 hours after the application. Air and surface temperatures must be above freezing during the application and for three days after. Mask glass, aluminum, metals, tiles, and plants.
SURFACE PREPARATION
To apply RadonSeal, the concrete surface must be bare and porous – paint, previous sealers, adhesives, oil, efflorescence, grease, etc., must be removed prior to application. Vacuum excessive dust, dirt, or loose particles. If the concrete is smooth (machine-troweled) you can improve surface porosity by acid etching or concrete grinding. Scuff sand hydrophobic surface levelers and patching compounds. Allow concrete to dry 2-3 days after power washing.
How To Safely Remove Efflorescence
APPLICATION
RadonSeal can applied with a low-pressure-hand-pump "garden" sprayer, paint roller (3/4" nap), or with a brush. Adjust nozzle on pump sprayer to a fan pattern. Shake or roll pail before use. Pull out the pouring spout and fill the pump sprayer.
1. Dampen The Concrete - use your sprayer, roller, or mop to dampen the concrete with water (breaks surface tension).
2. Apply RadonSeal In A Continuous Film – avoid puddles, do not overapply.
3. Apply A Second Application - 30 minutes later, while still damp, return to the beginning section and apply a second coat (concrete blocks require 3 applications).
The sprayed on film of RadonSeal should absorb within about 10 minutes (the surface still looks damp but there is no more gloss). If the concrete is unusually porous or alkaline, it will absorb very fast, letting you know that it badly needs more sealer – spray on another application. RadonSeal will not change the appearance or the profile of the concrete. It does not leave a surface film or color on the surface.
If you intend to paint the concrete floor, apply adhesive, epoxy, patching compounds, or surface levelers we advise you wash the concrete 2 hours after applying RadonSeal. Washing the concrete will ensure removal of any possible residue of the sealer.
4. Wash The Concrete Floor - Two hours after the final application, rinse the surface with water and lightly scrub with a push broom, shop vac or let dry.
RadonSeal will not change the appearance or the profile of the concrete. RadonSeal waterproofs concrete internally (2-4" inside) but does not make the surface water-repellent. The surface does not bead water and does not become slippery when wet. It will absorb water drops (it “wets”) but larger puddles will remain, because the concrete is waterproof.
Recent Feedback from Customers |
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...water was actually puddling in the middle of the room, coming up from under the concrete floor. I used the Radon seal and to my amazement ... no more water in fact no more moisture! That was 5 years ago.. .... Tom F., Atlanta, GA My cinder block wall was seeping water, so I sealed it with Drylock. But after several months, efflorescence pushed it out ... painted it again two times, but it always peeled and leaked again. ... your RadonSeal ... pushed out rivers of efflorescence from the concrete and it is now bone-dry... Brian D., NC ... finishing my basement and had great concerns about damp basement air, mold and mildew, and of course radon. Particularly, since we have a newborn in the house. ... My radon is now very low and the basement feels dry.... Mark W., MA ... a musty and damp basement and having two very allergic young children to mold and mildew. ... applied your Radon seal on the cinder block as directed and have not had any dampness in the basement anymore, ... Ken L., Edison, NJ ... relative humidity in the basement rooms would constantly hover between low 80% to high 70%. ... a definite “musty smell” ... Since applying the RadonSeal ... humidity is holding at 44 to 46% without the use of the dehumidifier! ... Jim M., GA ... The floor in my shop used to get wet from condensation every spring. It has worked GREAT! I have a dry floor year round ... Rick R., MN ... RadonSeal Plus to the block walls and (2) coats to the floor of my very damp basement. ... went from 5.1 pCi/L to 0.3 pCi/L. .. Traci T., DE See more Testimonials |
The RadonSeal spray-on application makes it an easy do-it-yourself home repair or home improvement project.
Info for Builders and Contractors
RadonSeal prevents or solves problems with moisture, molds, and radon in residential, institutional or commercial buildings like schools, apartments, hospitals, and hotels. It preserves commercial and industrial concrete assets indoors and outdoors – warehouses, factory floors and walls, cooling towers, water treatment plants, and bridges. It also protects parking areas, garages, and factory floors against oil spills and most chemicals. Info on RadonSeal Commercial Applications.
RadonSeal reduces costs and warranty callbacks, improves results, adds value, and increases customer satisfaction for a variety of contractors:
| Building contractors | Concrete contractors |
| Basement remodeling contractors | Waterproofing contractors |
| Radon mitigation contractors | Mold remediation contractors |
| Flooring contractors | Painting contractors |
