How to Paint Baseboards

Clean Previously Painted Baseboards

Nowhere is it more critical to clean the surfaces before painting than with previously painted baseboards (open-pore wood baseboards should not be cleaned with water). Dirt and grime collect at the bottom of walls, making this one of the dirtiest parts of the home.

Spread a drop cloth over the floor to protect it. Mix a solution of trisodium phosphate (TSP) with water in a bucket, according to product instructions. Wipe down the baseboards with the solution and a sponge. Be sure to clean the top of the baseboards, as dust naturally collects on horizontal surfaces.

Patch Gouges and Nail Depressions

Before you pull out the paint, patch and fill large dings and holes that developed over time, using wood filler applied with a putty knife. Large nail depressions should be filled, while tiny, pinpoint depressions can be left unfilled. If a brad nailer was used and the sink depth was perfectly calibrated, you may find it easier just to paint over those tiny divots. But if the baseboards were nailed by hand with finish nails, you should fill those holes with wood filler.

Lightly Sand

If you did significant patching with wood putty or filler, or if the baseboards are old, smooth them with fine-grit sandpaper before priming. Hand-sanding with a piece of sandpaper is usually fine, or you can use a flexible sanding sponge.

Sanding is more necessary with old baseboards that may already have several coats of paint.

Mask the Walls and Floor

Use low-stick painter's tape to mask the lower edge of the wall, right above the baseboards, as well as the junction between the floor and the baseboards. Even though masking is time-consuming, it will result in a faster and cleaner paint job. If you are a careful painter, a simple line of painter's tape covering the wall along the baseboard may offer all the protection you need. Masking does not guarantee perfect results, you still need to be careful when applying the paint, because excessive slop on the flooring-side masking tape will make it difficult to remove the tape after the paint dries.

For added protection in that baseboard-to-wall area, you can use masking film to ensure that the baseboard paint does not splatter on the wall. Run the masking tape edge of the film along the wall-to-baseboards junction, then spread the film upward. The film will stick to the wall on its own due to static electricity.

Some painters prefer to "freehand" when painting baseboards—painting without the benefit of masking. The cut-in painting technique (painting without masking off surfaces) is difficult enough on accessible door and window trim, but far more difficult on baseboards because of their location. It is simple to mask off baseboards because of the flat horizontal wall surface.

Prime the Baseboards

Baseboards that do not have factory-applied primer or a raw wood surface should always be primed before painting. Previously primed or painted baseboards can also benefit from a primer coat, but this is not always necessary if the cleaned surface is in good condition.

Mix the primer thoroughly. Dip the brush with primer but avoid overloading the brush, which can create drips and runs, then apply to the baseboards with horizontal strokes.

The best painting technique is to hold the brush between thumb and forefinger, as you would a pen, and draw the brush horizontally with the tips of the bristles slightly depressed against the baseboard. Load the brush with paint to about one-third of the bristle length. Long, slow strokes of the brush work best. As you progress along the baseboard, try to "keep a wet edge"—painting back over the edges of previously painted areas before the paint dries. This helps prevent lap marks.

Let the primer dry as directed by the manufacturer.

Paint the Baseboards

If your can of paint has been sitting for more than a few days, you may want to take it to the paint store to have it freshly shaken. Or, stir it thoroughly after opening the can. Set the can lid well away from the work area.

As with priming, be careful not to overload the brush with paint: Dip the brush to no more than one-third the length of the bristles. For the first coat, use less paint than you think you may need. Draw the paintbrush in long strokes along the length of the baseboards. As you overlap the strokes, try to keep a wet edge to prevent lap marks.

After the first coat, let the baseboards dry for at least one full day. After the paint has cured, apply a second coat. With high-gloss paints, some painters like to lightly scuff the painted surface with fine sandpaper before applying the second coat. This gives the glossy surface some "tooth" that helps the second coat adhere.

Wait for the paint to dry as directed, then remove the painter's tape.

Clean Your Tools

Use soap and water to thoroughly clean your brush, rollers, and any other painting tools or containers you will keep. A quality brush can last for years with proper care.