The importance of surface preparation cannot be underestimated when painting a floor. In order for the floor paint to stand up under harsh conditions, it must have good adhesion. And, that's only possible if the surface has been properly prepared.
To prepare a wood or concrete floor to be painted, the first step is a complete cleaning. The entire surface should be scrubbed with detergent and water. If there are still dirty areas, they should be spot cleaned. If oil or grease are a problem, you may have to use a specialty cleaner to do the job. And, if mildew is present, a solution of one part bleach and four parts water will remove it.
After the surface is cleaned, make sure to rinse it completely. Remember, the entire area must be free of oil, grease, dirt, or other contaminates, otherwise the paint will stick to the contaminates instead of the floor and the paint will ultimately fail.
On previously painted floors, all peeled or cracked paint must be removed prior to re-painting. And, if the previously painted surface is glossy, you need to dull it with a quick sanding so the new coat of paint will adhere properly.
If you are going to paint over bare concrete with a smooth surface, it needs to be etched first. Etching the area with a 5-percent muriatic acid solution will help open up the pores on the concrete, and allow the paint to adhere better. After etching, the area must be rinsed thoroughly, followed by another cleaning to neutralize any acid left on the surface.
If you want to paint over new concrete, the concrete must cure for at least 30 days and then be etched and cleaned before painting.
Any deteriorated or cracked areas on the floor must also be fixed prior to painting. Paint will not fill in cracks or solve problems with the substrate. For repair work, use a good patching compound such as Thoroseal or Rocktite for repairing concrete, and PlasticWood or Wood Dough for repairing wood.
Before you begin to paint, you must also allow the substrate to dry completely. Dampness can cause problems during the curing process, resulting in blistering, peeling, and poor durability. To test for excess moisture on a concrete surface, tape the edges of a 2 foot square sheet of plastic on the bare surface, sealing all of the edges. After 48 hours, if you find moisture, discoloration or condensation under the plastic, locate the source of the moisture and correct it before painting.
After the floor is in good shape, clean and dry, it's time to paint. You may think that a regular wall paint will do the job... but it won't. Floor paints, such as Do it Best Floor and Trim Enamel are specially formulated to be harder and adhere better so they can withstand foot traffic, scuffing, washing, and other conditions that would easily damage a wall paint.
Floor paints are also versatile. They can be used on a variety of surfaces like masonry, wood and metal. Plus, Alkyd floor paints are an excellent all-purpose enamel and can be used for woodwork, trim and a variety of other interior and exterior applications the need a durable finish. Because of the wear and tear that painted floors withstand, they usually need to be repainted every three to five years.
The same applicators and techniques you use with other surfaces are used when painting a floor. A brush will be needed around the edges, and a pad or roller will quickly cover the large areas. If a roller is used, use an extension pole that will allow the painter to stand, making the job much easier.