Damp Surfaces

To ensure penetration, the surface should be as dry as possible, clean, sound and free of any loose material. On surfaces subject to hydrostatic pressure, it is essential that all previous coatings and surface weaknesses be removed.
Concrete, Brick and Masonry
Concrete to be treated should preferably be dry and at least four weeks old and free of any soft surface laitance and contaminants. Thoroughly remove all loose material by wire brushing. Very smooth concrete or concrete with soft laitance should be etched with Watco Cemtetch and the area thoroughly washed off and allowed to dry. Grease or oil should be removed with Watco Bio D and the area thoroughly washed off and allowed to dry. Very porous surfaces may be primed with one coat of Watco Universal Sealer.
Surfaces with Algae or Fungal Growth
Remove all growths by wire brushing. Apply a fungicide to the surface allowing the surface to dry out between applications. Wash the surface thoroughly and allow to become as dry as possible. Failure to remove traces of the fungicide may result in poor adhesion of the Watco Dampshield.
Painted Surfaces
Remove all defective paint and create a key by rotary wire brushing, sanding etc.