There are literally hundreds of paints offered for use on concrete and selecting the correct one for a particular application on the basis of a brand name alone is just about impossible. However, a knowledge of the basic composition of a paint is the safest method of assessing its application potential. Cement-water paints consist of portland cement, usually white, ground together with several other components. The big advantage of cement-water paints is that they can be applied directly to a damp surface. Oil-base paints consist basically of a drying oil, thinners, pigments and driers. Oil-base paints present initially a glossy surface; they are so formulated, however, as to chalk with age. Varnish-base paints generally consist of a varnish made with resins, oils, solvents, driers, and thinners and pigmented for color and improved performance. These paints are suitable for surfaces exposed to severe moisture conditions from outside the concrete. Rubber-base paints generally consist of only resin pigment, solvent, thinner and plasticizer. Their main advantage is their outstanding alkali resistance. Water-thinned paints are largely based on rubber latex and have excellent washability. Bituminous paints have outstanding waterproofing agents but only come in black. Finally, epoxy paints are characterized not only by extreme chemical resistance but also by exceptional hardness, flexibility and adhesion. All paints should be stirred thoroughly before use by pouring back and forth a few times. Painting, like concreting, is best done under favorable climatic conditions. The method of application, whether spray, brush, or roller, is not particularly important and should rest to a large extent on economic considerations. Regardless of the method of application, it is important that the paint fill and seal the wall; for this reason it may be desirable in all cases to apply the first coat with a brush or by spraying. With good workmanship, a paint finish should prove visually and economically satisfactory. A knowledge of some of the faults may however save a few headaches later. (1) Loss of adhesion, blistering, peeling. This is usually due to water pressure behind the film. To fix, the source of the water must be removed or a water barrier must be put in place. (2) Framing, mottling. These are terms used, often for block construction, to describe the pattern of lines or patches of discoloration which appear through a paint. The cause is alkali attack either from within the concrete or without. (3) Wrinkling, alligatoring, checking are usually the result of uneven drying through the application of too thick a paint coat. (4) Mildew. The presence of mildew on a paint film is due to dampness in the atmosphere. A cheap method of removal is to scrub the area with a disinfectant.