Thompson's® WaterSeal® Waterproofer Plus Masonry Protector - Clear Aerosol

Waterproofer Plus Masonry Protector - Clear Aerosol

Provides proven waterproofing protection for exterior masonry surfaces. It waterproofs long after the initial water beading is gone.

Key Features

  • Prevents Water Damage
  • Coating Resists Mildew and UV Damage
  • Helps Maintain Natural Color - Dries Clear
  • Use On: Terra Cotta Planters, Concrete Benches and Other Exterior Masonry Surfaces

Approximate Coverage

  • 25 Sq. Ft/Can

Before You Begin

  • When applying this product wear a dust/mist filtering respirator (MSHA/NIOSH approval number prefix TC-21C), or a NIOSH approved respirator with any R, P, or HE filter.
  • Be sure that both surface and air temperature are above 40° F during application and for 48 hours after application. Do not apply product if rain is forecasted within 24 hours of application.
  • Perform the splash test. Sprinkle water on various sections of surface to be sealed. If water absorbs and darkens color of surface within five seconds, surface is porous and considered ready to be treated. If water beads up or otherwise sits on top of surface, then surface does not need protection at this time.
  • Certain surfaces, including some stucco and stabilized adobe may “bleed” in the presence of solvents, thereby resulting in discoloration. Test in an inconspicuous area before treating the entire surface.
  • Cover plants and shrubs. Move all objects that could come in contact with overspray. Overspray of product onto glass should be removed immediately with paint thinner or mineral spirits, following manufacturer’s safety recommendations.
  • Do not use on asphalt, plastic, natural rubber or fabric, or on painted or recently stained surfaces.

Surface Preparation

  • Surfaces and substrates must be free of all mildew stains, dust, dirt, oil, soot, grease and other contaminants.
  • Surfaces must be thoroughly cleaned prior to application with a concrete cleaner applied according to label directions and cautions.
  • If surface is damp or wet from cleaning or weather, always allow the surface to dry thoroughly (minimum of 3 days) before application.


  • Do not mix with other waterproofing products; variations in the final appearance may result.
  • A small trial patch should be tried before application over the entire surface.
  • Shake can well; hold can in upright position 12” from surface. Spray one thin coat over entire surface to be waterproofed – DO NOT SATURATE.
  • If applying a second coat, allow first coat to dry for 24 hours.
  • Use only with adequate ventilation.
  • Oiliness and tackiness will result if over-applied, applied to wet or damp surface, or if overnight temperature falls below 40° F within 48 hours of application.


  • Allow at least 48 hours to dry.


CAUTIONS: CONTAINS ALIPHATIC HYDROCARBONS. DANGER! EXTREMELY FLAMMABLE. Keep away from heat, sparks, and open flame. Vapors will accumulate readily and may ignite explosively. Keep area ventilated during use and until all vapors are gone. DO NOT SMOKE - Extinguish all flames, pilot lights and heaters - Turn off stoves, electric tools and appliances, and any other sources of ignition. CONTENTS UNDER PRESSURE. Avoid prolonged exposure to sunlight or heat from radiators, stoves, hot water and other heat sources that may cause bursting. Do not puncture, incinerate, burn or store above 120°F. Keep upright in a cool, dry place. Do not discard empty can in trash compactor. VAPOR HARMFUL. Use with adequate ventilation. Avoid continuous breathing of vapor and spray mist. To avoid breathing vapors or spray mist, open windows and doors or use other means to ensure fresh air entry during application and drying. If you experience eye watering, headaches, or dizziness, increase fresh air or wear respiratory protection (NIOSH approved) or leave the area. Avoid contact with eyes and skin. Wash hands after using. FIRST AID: In case of eye contact, flush thoroughly with large amounts of water for 15 minutes and get medical attention. For skin contact, wash thoroughly with soap and water. In case of respiratory difficulty, provide fresh air and call physician. DELAYED EFFECTS FROM LONG TERM OVEREXPOSURE: Contains solvents which can cause permanent brain and nervous system damage. Intentional misuse by deliberately concentrating and inhaling the contents can be harmful or fatal. DO NOT TAKE INTERNALLY. KEEP OUT OF THE REACH OF CHILDREN.

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