Wooden floors can be finished in many ways--they can be varnished, stained, lacquered, polyurethaned or painted. Painting a wooden floor is a great way to add colour to any room without installing carpet or tile, and it's inexpensive, too. However, not all paints can be used on a wooden floor. You will need to use a paint that is made especially for floors, because a regular latex paint will quickly peel and chip once the floor is walked on. A floor paint is more durable and can stand the wear and tear of foot traffic.
Use an electric handheld sander and a medium-grit sandpaper to completely remove the old finish from the floor. If the floor does not have a finish on it, it will still need to be sanded. Sanding the floor gives the paint a smooth surface to stick to, making it adhere better. Sanding also removes any nicks, dents, scratches and splinters in the wood. Once you have sanded the floor using the medium-grit sandpaper, change the sandpaper to fine grit and go over the floor again. This will give you the smoothest possible floor surface.
Use a shop vacuum or a regular vacuum cleaner to remove all of the dust particles on the floor. The paint will not adhere to the wood floor properly if any dust remains. The dust may also get trapped under the paint and cause bubbles, bumps and blemishes in the finish. You will have more success removing all of the dust particles with a vacuum than with a broom and dustpan.
Use painter's tape to tape off the bottom edges of the walls in the room. Use the tape to cover baseboards and moulding so that the floor paint does not get on them. If you need to cover a large area, use newspaper and painter's tape.
Fill your paint tray with an oil-based floor paint. Use a small paintbrush or an edger to do all of the edges around the perimeter of the room. The edges need to be done first because you will not be able to step on the main floor surface once you have painted it. Use a roller to apply the paint to the rest of the floor, beginning on the far end of the room and working your way toward the exit. Allow the paint 24 hours to dry. Apply another coat of paint for added coverage and colour richness. Allow the second coat of paint to dry for 24 hours, too.
Use a clean edger or paintbrush to apply a coat of polyurethane to the edges of the floor. Use a clean roller to apply the polyurethane to the rest of the floor's surface. Allow one hour to dry, then apply another coat. The polyurethane will help to protect the paint, and will make the floor more water-resistant and easier to keep clean. Allow the polyurethane three to four hours to completely dry before using the floor. Use a mop and gentle cleaner to clean the floor when needed.
Do not walk on the floor until it is fully dry, or damage to the surface will result. To skip the polyurethane application, choose an oil-based floor paint that has polyurethane added to it. Know, though, that applying polyurethane separately after painting will better protect the surface from damage.
Ventilate while sanding, and wear a face mask. Ventilate while painting and applying polyurethane.