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303WB Water-Based Siloxane Water Repellent


7% & 15%

303WB is a VOC compliant, penetrating, breathable, siloxane product for use on precast and site cast concrete, clay and concrete masonry, sandstone and stucco surfaces where surface darkening is unacceptable.

  • Reduces bonding of airborne dirt and hydro-carbons
  • Reduces water damage caused by freeze/thaw cycles
  • Provides protection against efflorescence and exhibits excellent resistance to ultraviolet rays and chlorine ions
  • Exceeds requirements of NCHRP 244, meets SSW 110C Federal Specification and ASTM E514

Formulated for use on Precast And Site Cast Concrete, Clay and Concrete Masonry, Sandstone and Stucco Surfaces where surface darkening is unacceptable


  • NOT recommended for marble, travertine, limestone, polished granite, gypsum, plaster or syntheic resin paint
  • Do NOT allow product to freeze, store at room temperature (65°F)

Water-Based Siloxane Water Repellent Application

    • Air and surface temperatures must be 40°F or higher at time of application, do NOT apply product when rain is expected within 4 hours.
    • Re-pointing should be done and allowed to dry before application, caulking must be done and allowed to cure or until material is set, as per manufacturer's instructions.
    • Protect surrounding non-masonry surfaces such as glass, aluminum, painted surfaces etc., any inadvertent drips, splashes or runs should be removed with water before solution has dried on the surface.
    • Apply at full strength using a low-pressure sprayer for optimum performance.
    • Work from bottom to top applying a light mist and then following up with a full flood coat with minimum 8” to 12” run down.
    • A second coat may be necessary on extremely porous surfaces.
    • Apply a single saturating application for horizontal surfaces, taking care to brush out any pooling liquid.
    • For detailed instructions, download the Technical Data Sheet for this product.
    • Suggested Dilution Rates for 300WB Water-Base Siloxane Water Repellent
Must be applied as packaged and per recommendations, do not alter or dilute this product
    • Coverage Rates for 300WB Water-Base Siloxane Water Repellent
Project Materials/Conditions Coverage
Clay Brick 100-150 sq. ft. per gal.
Cement Brick 80-120 sq. ft. per gal.
Concrete Block 60-80 sq. ft. per gal.
Smooth Concrete (precast) 100-150 sq. ft. per gal.
Smooth Concrete (steel troweled) 150-200 sq. ft. per gal.
Stucco 125-175 sq. ft. per gal.
Exposed Aggregate 100-150 sq. ft. per gal.
Natural Stone (Rock Face) 100-150 sq. ft. per gal.
Natural Stone (Smooth Cut) 125-175 sq. ft. per gal.

              Technical Data Sheet

              Safety Data Sheet

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