Painting exterior brick can transform the look of an outside wall or an entire house. Paint is also a handy disguise for brick walls that have been altered, for example when a window or door is moved or resized. Proper surface preparation and paint selection is the key to a successful, long-lasting paint job.
Purchase a high-quality exterior latex paint. Latex paint is porous and allows exterior surfaces to "breathe," which is recommended for all exterior applications. Some exterior paints combine paint and primer in one product. A matt finish paint usually looks best for large painted surfaces such as the walls of a house.
Examine the surfaces you plan to paint for evidence of moisture penetration, since this will shorten the life of your new paint job. Signs to look for include a powdery crust, mould, mildew and moss. Determine the source of the moisture and make any necessary repairs such as tuckpointing, caulking or flashing repair.
Prepare the brick surface. Scrape off any loose or flaking paint with a paint scraper or stiff wire brush. Remove any chalky white residue with water and a wire brush. Small areas of mildew can be removed with a household cleaner or a solution of trisodium phosphate and water; use a medium-soft brush. If you're painting over a coat of glossy paint, rough up the surface with sandpaper to help the new paint adhere.
Wash the entire surface with water--a power washer works well for large areas. Allow the surface to dry thoroughly. This may take a day or more.
Check the weather report before you begin painting. Ideal painting conditions are dry, not too windy and from 18.3 to 29.4 degrees Celsius. The lowest recommended temperature to apply latex paint is 10 degrees Celsius.
Lay down paint dust sheets to protect the area under and near the surface you'll be painting.
Prime any areas where the brick is exposed. If you're painting a brick surface for the first time, you should prime the entire surface. If you're working on a previously painted surface, only prime those spots where unpainted brick is visible. Start at the top of the surface and work your way down. Allow the primer to dry fully. There is no need to prime if your topcoat paint is self-priming.
Apply a first layer of paint. Use a quality nylon paintbrush for edges and cutting in around windows, doors and other adjoining surfaces. Paint large surfaces with a high nap, fluffy roller or a paintbrush. Paint from the top of the surface down. Latex paint dries quickly. When using a brush, paint with long, smooth strokes and don't brush the same spot repeatedly. Work in 3-by-3 foot sections rather than trying to paint the entire area at once. Allow the paint to dry fully.
Apply a second coat of paint using the same method.
Avoid painting in direct sunlight. This will cause the paint to dry too quickly and create blisters and brush marks.
The paint on older, previously painted homes may contain lead. If this paint is loose or flaking, contact a government office or a qualified lead abatement company for advice on how to remove it safely before beginning your paint project.