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Home » Procedures » Sealing Deteriorated High-Strength Floors

Sealing Deteriorated High-Strength Floors


Molds and mildew, dampness, water seepage

Examples of Floors

Floors in factories, prisons, warehouses, governmental or commercial buildings.
Typically, high-strength concrete (6 – 8,000 psi), 2 – 3 ft. thick.

Application Procedure

  1. Surface preparation:
    Remove molds and mildew, paint or wax, adhesives, efflorescence, and if applicable, open up the surface (see Surface Preparation below)
  2. Dampen the concrete:
    Spray with water. Or, flood the surface with water, squeegee off puddles, and let partially dry for 30 minutes.
  3. Spray on RadonSeal:
    Use a mobile pesticide sprayer powered by battery or gasoline engine or hand-pump sprayers. Or an airless sprayer set at 40-60 psi with a lacquer tip and a long hose (100-150 ft.) for mobility.
    Spray on RadonSeal Standard in two successive continuous-film applications.
    Coverage rate – 150 to 125 sq. ft./gallon for each application. Do not over-spray, spread out any puddles with a broom.
    Apply the 2nd application while still damp, 15 to 20 minutes after the 1st.
    Note: Extremely porous areas, which absorb the sealer in less than 1 minute, will need a 3rd successive application while still damp.
  4. Clean-up:
    In 6 to 12 hours after sealing, hose off the surface with water and scrub with a deck brush to remove any residue. Or use a commercial floor scrubber. Within the first several days, RadonSeal will purge minerals, dirt, and efflorescence from the concrete – sweep up or shop-vac.

Note: In case there is still excessive water vapor transmission after 30 to 60 days of curing, the concrete requires a secondary sealer – Ion-Bond Armor. Alternatively, let the concrete dry out for 10 days and spray on 2 applications of Ion-Bond Armor.

Surface Preparation Methods

Shot-Blasting – the preferred method for complete cleaning and opening up the surface, removing paint or efflorescence. Alternative methods – a disk sander with 16 grit sandpaper, a diamond grinder, a scarifier, sand-blasting, water-or soda-blasting.

Molds and mildew:
A solution of chlorine bleach (25–50%) or borate with detergent, or RadonSeal Efflorescence Cleaner. The safer solution for indoors is BioZap Mold and Mildew Cleaner. Call a professional for extensive mold infestation.

Paint or adhesives:
Sand- or water-blasting. RadonSeal paint stripper, or Universal Concrete Cleaner for latex or acrylic paints.

Shot-blasting, steel brushes or RadonSeal Efflorescence Cleaner.

Novion Universal Concrete Sealer.

Sweep and shop-vacuum. Clean with Universal Concrete Sealer.

Hard-cap surface:
A very smooth, shiny finish from excessive power-trowelling. Use the “eyedropper test” to check porosity. Shot-blasting or sand-blasting.