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NWRT-91: Nawkaw Water Repellant Treatment


NWRT-91 is a dual purpose product—a stain for masonry and concrete, plus a water repellent. It enables you to color and protect vertical masonry and concrete surfaces in one easy step. NWRT-91 repels water and protects the masonry against deterioration caused by airborne chemicals including acid rain. NWRT-91 allows moisture vapors to escape and therefore does not promote spalling or similar failure due to moisture trapped in the wall.

Nawkaw Water Repellant Treatment (NWRT-91) is a hydrous, multiple polymer formulation of resin solids, color pigments and a specially formulated tint base, combined to achieve a wide range of colors designed to exhibit the overall characteristics of being: light fast, UV resistant penetrating, aspiratory, and quick drying, while being mold, mildew, fungus and weather resistant. NWRT-91 includes a quality water repellent for added protection.


80-240 sq ft per gallon depending on the absorbency of the substrate


  • Solids (wt) 36-39 %
  • Solids (vol) 31-34 %
  • Specific Gravity: 1.27 – 1.31
  • Viscosity (72° F): 70°-95° KU
  • pH: 8.5-9.5
  • Gloss: Flat
  • Flash Point: None
  • Volatile Organic Content (VOC) <5%
  • Abrasion Resistance: Excellent
  • Penetration: Dependent on Substrate
  • Tack Free Time: 3/4 - 1 1/2 hours
  • Water Repellency (ASTM C67-80a) Min. Penetration
  • Dry Time for reapplication (if required) 4 hours
  • Curing: allow 21 days
  • Shelf Life 6 months in factory sealed container


  • Coverage rate varies with concrete quality and finish
  • Brush, roll or spray


  • Brick, Block & mortar
  • Concrete
  • Concrete Block
  • Precast
  • Tilt-up
  • In situ


  • Verify that any masonry, concrete, stucco walls that have been treated with any form of chemical/acid wash are neutralized.

  • Verify that masonry, concrete, stucco, in existing building are structurally sound and fully intact.

  • Alkali or efflorescence should be treated with proper neutralizing compounds as recommended by masonry supplier before application can begin. Walls must have a neutral pH for product warranty to be in effect.

  • Application of NWRT-91 is possible in temperatures of 25°F to 110°F. Masonry surfaces should be dry before work begins.

  • NWRT-91 is applied by spray, roller and hand applications depending on the desired finish.


NWRT-91 is environmentally friendly, water-based, non-flammable and complies with VOC and other appropriate Government safety standards, legislation and regulatory requirements.

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