RadonSeal Plus Concrete Sealer

Deep-Penetrating Concrete Sealer for Permanent Waterproofing RadonSeal Plus is a deep-penetrating concrete sealer designed to permanently waterproof, strengthen, and protect poured concrete and concrete block. It penetrates up to 4 inches below the surface and reacts inside the concrete to seal the pores and capillaries that allow water, moisture vapor, and soil gases to pass through. Unlike surface coatings, RadonSeal forms a permanent cementitious barrier within the concrete itself — resisting both positive and negative-side hydrostatic pressure while densifying and hardening the surface. Basement Waterproofing Sealer RadonSeal Plus is one of the strongest and deepest-penetrating basement waterproofing sealers available. It helps stop water seepage through basement floors and foundation walls, reducing dampness, musty odors, mold and mildew growth, and moisture-related damage. Seal your concrete slab and foundation walls before finishing your basement to protect drywall, flooring, insulation, and stored belongings from hidden moisture intrusion. Treated surfaces remain natural and ready for paints, adhesives, tile, overlays, epoxy coatings, urethane systems, or finished flooring. Unlike surface waterproofing paints or membranes, RadonSeal penetrates into the concrete itself — creating long-term protection without peeling, blistering, or reapplication. Radon Mitigation RadonSeal Plus helps reduce radon and other soil gases from entering homes, schools, and workplaces by restricting their movement through concrete floors and foundation walls. By sealing the pores and capillaries within the concrete, RadonSeal limits pathways that allow radon gas to migrate indoors. RadonSeal can be used as part of a radon mitigation strategy — either as an alternative approach in certain situations or in conjunction with an existing fan-based radon reduction system to help further lower indoor radon levels. For best results, seal cracks, control joints, and penetrations before application. Always test radon levels before and after mitigation to verify performance and ensure levels are below the EPA action guideline of 4 pCi/L. Strengthen & Preserve Your Concrete RadonSeal Plus permanently strengthens and densifies concrete by reacting within the slab to form additional cementitious structure inside the pores. This internal densification increases surface hardness, reduces dusting, and improves resistance to cracking and surface deterioration. Ideal for exterior concrete such as driveways, aprons, parking garages, seawalls, warehouse floors, and other surfaces exposed to freeze-thaw cycles, deicing salts, and road chemicals. By reducing water absorption, RadonSeal helps protect concrete from efflorescence, spalling, scaling, and long-term moisture damage. Unlike film-forming sealers, protection occurs within the concrete itself — preserving the natural appearance while enhancing durability. Zero-VOC, Water-Based & Easy to Apply RadonSeal Plus is a water-based, zero-VOC concrete sealer with no odor, no hazardous solvents, and no flammable chemicals. Safe for interior and exterior use, it can be applied in basements, garages, and occupied spaces without disrupting your home or workspace. Application is simple — apply by brush, roller, or low-pressure sprayer to clean, bare concrete. No mixing, no surface film, and no special ventilation required. Once absorbed, RadonSeal provides permanent protection without changing the natural appearance. The Permanent Concrete Sealer RadonSeal becomes part of the concrete itself — forming a permanent internal seal that will not crack, peel, blister, or fade. No reapplication is required. Once treated, the protection remains within the concrete for the life of the structure. Resistant to both positive and negative-side hydrostatic pressure, RadonSeal provides long-term waterproofing and durability without coatings or membranes that can fail over time. Lifetime Money-Back Guarantee We stand behind the performance of RadonSeal Plus with a Lifetime Money-Back Guarantee. If it does not perform as described when applied according to instructions, contact our technical support team for assistance. Trusted since 1997. Exclusions: Stamped concrete, integrally colored or acid-stained concrete, polished concrete floors, modified hydraulic cement, fiber-reinforced concrete, exterior split-face or lightweight concrete blocks, bricks, or pavers. Hard-troweled or steel-troweled concrete surfaces may require mechanical or chemical etching to ensure proper absorption. Need Help with Your Project? Our knowledgeable technical support team is just a phone call or email away. We’re here to help you get the job done right. Fast Shipping Most orders received by 2:00 PM EST ship the same business day via Ground Delivery. Delivery typically takes 1–3 business days to the East Coast and Central states, and 3–5 business days to West Coast destinations.