TABLE OF CONTENTS Water-repellent coatings are often applied on architectural concrete block and on some light-colored stone, but their effectiveness is usually limited to a period of three to seven years, depending on the product selected. Water-repellent coatings can be applied in one of three ways, depending on the size of the surface being treated:
With a synthetic bristle paint brush
With a synthetic roller and plastic paint roller pan
With low-pressure (20-psi) spray equipment with a stainless steel fan tip nozzle.
When water repellents are applied by sprayer, sheets of plastic should be used to protect adjacent surfaces and landscaping. The application of water-repellent coatings does not require any special skills or equipment, but manufacturer s label instructions should be followed for handling, application rates, cleanup, and disposal. Some products contain VOCs (volatile organic compounds), the use of which may be restricted in some areas, and the disposal of which is regulated in almost all areas.
The surface to which the coating will be applied must be clean and free of dirt or oils that would prohibit absorption of the coating into the surface. If general or spot cleaning is necessary, the surface should be allowed to dry thoroughly before proceeding. The mortar in new masonry walls (or freshly placed concrete) should fully cure for at least 28 days before applying a water repellent. Water-based coatings will have less odor than solvent-based products.
Spray applications should be made only when there is little or no wind...
