An old brick wall can appear dingy and dirty, but adding a fresh coat of paint can help brighten the space and create a cleaner, more even finish. The rough texture of brick gives a good surface for paint to adhere to, but due to its porosity, it tends to absorb much more paint — anywhere from 20 percent to 50 percent more — compared to a typical wall. Filling cracks and gaps beforehand and touching up paint in the grooves between bricks adds more work also, so allocate extra time for this as well.
Protect furniture and flooring from paint drips by covering them with canvas or plastic dropcloths.
Scrub the brick gently with a stiff nylon brush, and then vacuum the surface to remove any loose mortar, dirt or dust. Fill a bucket with clean, warm water and mix in a few drops of liquid soap. Wash the bricks using the soapy mixture to remove any remaining dust or soot and allow the surface to dry for at least 12 hours. If the brick feels cold, it probably needs to dry a bit longer.
Fill cracks and gaps in the mortar joints between bricks with spackling compound for smaller holes and cracks and caulk for bigger gaps and crevices. This reduces the amount of primer and paint needed and makes a smoother finish.
Attach painter’s tape to any adjacent walls or trim that you don’t need to paint.
Apply primer to the brick surface beginning at the corners and edges using a 2- to 2 1/2-inch-wide nylon polyester brush. Pour some primer to your paint tray and then cover the rest of the brick surface utilizing a 1/2- to 1 1/4-inch nap roller, based on the roughness of the brick. A thicker roller may push primer into bigger grooves and pores. Use a paintbrush to cover the mortar joints using primer. Allow the primer to fully dry.
Paint the wall using a top-quality, water-based, acrylic paint intended for interior use. Using a paint roller first, try to cover as much of the brick and mortar as you can. Implement more paint with a brush across the perimeter and into the mortar joints between bricks in which the roller missed. Allow the paint to dry and apply another coat if needed.
Eliminate the dropcloths and painter’s tape once the paint is dry.