How to Prepare an Old Concrete Garage Floor for Paint
- 1). Remove everything from the garage and thoroughly vacuum the garage floor.
- 2). Clean oil stains with an alkaline detergent to remove grease and stains. Avoid overuse of alkaline detergent, which can be an environmental hazard. Spot clean the soiled areas by pre-treating with alkaline detergent. Mix alkaline detergent with water to make a thin paste and pour on grease or oil stains. Allow to soak for a few hours.
- 3). Wash with a pressure washer with hot water. Use a 0-degree blasting nozzle to clean the concrete and a 25-degree cleaning nozzle to rinse. Use smooth, even strokes and work from one side of the garage to the other, one section at a time.
- 4). Repair cracks with an epoxy crack filler with sand pre-mixed into the product by the manufacturer. This is suitable for most common cracks and wide, shallow cracks. Fill with the epoxy crack filler and level to existing concrete. For deep cracks, fill the crack with some plain sand so there is approximately 1/2 to 1 inch remaining to fill with the epoxy crack filler.
- 5). Allow the concrete to dry thoroughly after cleaning and crack repair. Refer to drying times on the concrete-crack-filler label to calculate drying time.
- 6). Apply a concrete primer and concrete paint by the same manufacturer. Products developed by one manufacturer are designed to work together. General, all-purpose primer was not developed for adherence to concrete. Allow the primer to cure according to the directions on the label before painting.