When dealing with porous surfaces such as natural stone, concrete, brick, or slate, it is important to protect against water, dirt, mildew, and stains. Porous substrates will absorb liquids which can stain, discolor, and/or affect the structural integrity of your surface.
Penetrating sealers are not coatings, but instead “penetrate” chemically with the concrete pores to create a hydrophobic substance. This seal is made by creating an atmosphere that does not allow water to penetrate. Surfaces that have been treated with penetrating sealers do not significantly change in appearance, leaving a “natural look”. This allows water to just “bead” on the surface when introduces to a treated concrete surface.
How to Apply Penetrating Sealers
Prior to applying sealer always test a small area to verify penetration and satisfaction of appearance. Allow 24-hours to dry and cure. Apply to saturation with brush, roller or spray device, one liberal coat. However, DO NOT allow any excess sealer to remain on the surface. Any sealer not absorbed in 1 to 2 minutes must be immediately removed by wiping and polishing with dry, absorbent rags. On vertical surfaces start at the top and work down keeping a “wet edge” at all times. Avoid run-down and overlapping. In 4-hours, substrate can be tested for water repellency by sprinkling water drops on surface. If water beads and does not penetrate, repellency is satisfactory. On exceptionally porous surfaces, a second coat may be necessary. If applying a second coat, it is critical not to allow ANY sealer to dry on the surface. Glass, aluminum, glazed tile and other surfaces should be protected from sealer contact. The alkalinity of this sealer may damage lawns and shrubs; protect with a drop cloth.
100 to 700 square feet per gallon depending on porosity of the surface and method of application. Apply sealer between 50º and 80º F. On warm days, porous and semi-porous surfaces may be lightly dampened with water prior to sealer application. Do not apply sealer during rainy conditions or if rain is anticipated within two hours of application.