Since 1997 - Waterproofing solutions are not always simple but with a little know-how and the right advice permanent fixes can be accomplished relatively easy and inexpensive. For over 16 years, RadonSealÂ® has been dedicated to offering homeowners and contractors unbiased expertise, unparalleled service and our professional-quality, ready to use, concrete sealers, brick sealers, and concrete repair products. RadonSealÂ® Plus Concrete Sealer is formulated to seal more porous concrete like; poured concrete >20 years old, concrete blocks, and porous cinder blocks. Depending on porosity, RadonSealÂ® Plus is able to penetrate 4 into concrete, where it chemically reacts, seals, and strengthens concrete internally. Treated surfaces are permanently sealed against water seepage, water vapor, and even radon gas. Stops efflorescence, concrete dusting and prevents mold growth and staining. RadonSealÂ® seals, strengthens, and densifies, concrete floors and walls, indoors or outdoors. Ideal for basements where humidity and/or water seepage is a concern. Use on concrete slabs, garage floors, foundation walls, parking structures, and warehouse and factory floors. Prevents concrete pitting and spalling due to freeze-thaw, road salts, and chemicals. Safe and easy spray-on application for homeowners or contractors. Approx. coverage per 5 gallon pail: Poured Concrete - 1000 sq. ft., Concrete Block - 500 sq. ft., Cinder Block - 400 sq. ft. We know from experience that sealing concrete is not always cut-and-dry. If you have questions about your particular concrete or project please contact a RadonSealÂ® service technician at 1-800-472-0603.