Let’s start with the question; What is radon? Radon is a chemical element with symbol Rn and atomic number 86. It is a radioactive, colorless, odorless, tasteless noble gas, occurring naturally as a decay product of radium. Its most stable isotope, ²²²Rn, has a half-life of 3.8 days.

Now that we have identified that Radon is in-fact a “gas”, how do you prevent the radon from passing up from below your foundation and into your home or business. Concrete is very porous and will allow both moisture and vapors/gases to pass from below, especially if the pressure below the concrete is abnormally high.

The idea is to reduce porosity or congest the pores within the concrete to reduce or completely stop radon gas by selecting the best radon concrete sealer. Radon concrete sealers come in both breathable and non-breathable forms. All Penetrating radon concrete sealers are considered “breathable” which means under pressure from below they will still allow moisture, vapor and radon to pass through the concrete. In most test cases that we have performed a penetrating radon concrete sealer such as sodium silicate, lithium silicate, silane or other forms of silicone-based materials will reduce moisture/vapor transmission by 15-45% still leaving anywhere from 55-85% of the radon passing up through the pores and capillaries of the concrete which is why a non-breathable radon concrete sealer is more ideal to drastically reduce radon levels.

Non-Breathable radon concrete sealers are ideal for highly reducing or completely block radon from passing through concrete. It is important to properly prepare the concrete by acid etching or more favorably machine grinding the surface to allow a non-breathable sealer - coating to better absorb and bond to the concrete. With a micro resin epoxy (epoxy primer) you can see a drastic reduce moisture/vapor transmission by 45-80% with one single coat and 85-100% with a proper 2-coat application.

Additional thoughts to consider when looking for a radon concrete sealer are the alternate ways that radon can transmit into your home or business. “You can seal your concrete so that nothing will pass through the concrete, but if you have bulkheads, pipe penetrations/fittings, foundation cracks, deep control joints, sump pump pits, French drains, unsealed cold joints/seams, etc then you must address every potential point of entry to reduce or stop radon from entering you home or business”.


Armor SX5000 Penetrating Silane Siloxane Concrete Sealer and Masonry Water Repellent (5 GAL)

Armor AR350 Solvent Based Acrylic Wet Look Concrete Sealer and Paver Sealer (5 GAL)

Armor AR500 Solvent Based Wet Look High Gloss Acrylic Concrete Sealer and Paver Sealer (5 GAL)

Armor UTN60 Oil and Gas Resistant Aliphatic Urethane Concrete Floor Coating

5 GAL Armor S2000 Concentrated Sodium Silicate Concrete Densifier Sealer and Surface Hardener

Armor SC25 Siliconate Water Repellent Concrete Sealer with Salt Guard (1 GAL)