Actual coverage will vary considerably due to porosity of surface materials.

Material (approximate coverage sq. ft./gal.)
Brick 175
Concrete 250
Smooth Concrete Block 50
*Clay Tile & Quarry Tile 250
Stucco 250
*Slate - Masonite 375
Wood: Rough Sawn 100
Wood: Smooth Finish 200
Plywood 150
Wood Shingles 100

*Wipe surface dry after 5-10 minutes.

Before you begin

  • For Exterior Use Only.
  • Be sure that both surface and air temperatures are above 50° F during application and remain above 40° F 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 substrate 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.
  • Cover plants and shrubs. Move all objects that could come in contact with overspray. Wet overspray of product can be removed by flushing immediately with water. Dried overspray can be removed with paint thinner or mineral spirits, following manufacturer’s safety recommendations.
  • Do not use in below grade application where water pressure is a problem, or on painted or recently stained surfaces.
  • DO NOT USE AS AN ADDITIVE TO PAINT.
  • Protect product from freezing. Do not store below 32° F. In case of accidental freezing, call The Thompson’s Company Help Line.

Surface preparation

  • Surfaces and substrates must be free of all mildew, dust, dirt, oil, soot, grease and other contaminants.
  • For Concrete/Brick/Masonry: Surfaces must be thoroughly cleaned prior to application with a concrete cleaner applied according to label directions and cautions. Concrete that has a smooth, flat finish must be opened for proper penetration. This should be done using a concrete etch product. Follow etching product use instructions carefully and ensure thorough rinsing and removal of etching solution. Allow concrete to dry a minimum of 72 hours after etching before applying a waterproofer.
  • For Wood: Surfaces must be thoroughly cleaned prior to application with a deck cleaner (like those in the Thompson’s WaterSeal Deck Cleaner line) applied according to label directions and cautions. Once wood surface has been cleaned, wait 3 hours before applying Thompson’s WaterSeal Clear Multi-Surface Waterproofer.

Application

  • Do not mix with other waterproofing products; variations in the final appearance may result.
  • Do not thin.
  • Concrete/Stucco must be completely cured (minimum of 4 weeks) and dry.
  • Shake contents well before use.
  • A small trial patch should be tried before application over the entire surface.
  • Only one light coat is necessary in most applications.
  • Apply by brush, roller, or sprayer. A garden "pump-up" style sprayer is the simplest method. Product will appear milky white during application, but will dry clear.

    If puddling of product occurs, remove within 15 minutes by redistributing to dry areas or wiping off.
  • Use only with adequate ventilation.
  • See Coverage Guidelines on side panel.
  • Tackiness will result if over-applied. May also occur after application if overnight temperature falls below 40° F within 48 hours of application.

Drying

  • Allow at least 24 hours to dry; however drying time will vary depending on the substrate, temperature, and humidity. When completely dry, do splash test to determine if second coat is necessary.
  • Allow 45 days drying time before applying latex paint over Thompson’s® WaterSeal® Clear Multi-Surface Waterproofer.
  • Allow a minimum of 3 days drying time before applying oil based paint over Thompson’s® WaterSeal® Clear Multi-Surface Waterproofer.
  • Length of protection will vary depending on environment. Perform the splash test once a year to see whether reapplication is necessary. Vertical and horizontal surfaces will experience color changes at different rates.

Clean Up

  • Clean brushes and equipment with mineral spirits following manufacturer’s safety recommendations, then rinse with soap and clean water.