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SL40 Water Repellent — 40% active silane treatment for durable, invisible protection on concrete and masonry surfaces.

Prosoco SL40 Water Repellent

PROSOCO SL40 Water Repellent is a clear, penetrating silane water repellent containing a solution of silane reduced in solvents. SL40 protects horizontal and vertical concrete and masonry surfaces against water and waterborne contaminants. The product’s low viscosity and small molecular size allow maximum penetration into the concrete or masonry surfaces.
PROSOCO SL40 Water Repellent chemically reacts with the substrate to produce a long-lasting water repellent effect. Surfaces treated with SL40 maintain their natural appearance, vapor permeability, slip resistance, and other surface characteristics. Depth of penetration is controlled by the application rate (loading rate).

This is a special-order product. Production lead times and quantity minimums may apply.

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40% Active Silane Water Repellent
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Product Description

SL40 Water Repellent is a clear, penetrating silane solution designed to deliver deep water repellency to horizontal and vertical concrete and masonry surfaces. With a 40% active formula, it provides durable protection against moisture intrusion, weathering, and deicing salts without altering the natural appearance of the surface.

Key Benefits

  • Deep Penetration: Allows maximum diffusion through small molecular structure.
  • Breathable Barrier: Treated surfaces remain vapor-permeable and do not trap moisture.
  • Surface Safe: Does not form film or gloss and leaves little or no residue on windows.
  • Protection from Salts: Reduces efflorescence and corrosion due to waterborne salts.
  • Efficient on High-Traffic Surfaces: Suitable for vehicle-exposed areas and polished concrete.

Best For

  • Concrete masonry
  • Cured or honed concrete
  • Exterior walkways and driveways
  • Exposed aggregate
  • Polished horizontal surfaces

Product Properties

Property Specification
Form Clear, colorless liquid Alcohol odor
VOC Content 600 g/L maximum
Active Content 100%
pH N/A
Coverage Rate 100–400 sq.ft./gal. See Product Data Sheet for variations per substrate.
Flash Point 35°F (2°C) ASTM D 3278
Wt/Gal 7.01 lbs
Available Sizes 5 gal, 55 gal
Water Vapor Transmission 90% retention ASTM D6490
Shelf Life 1 year in tightly sealed, unopened container

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