Brick cleaning solutions are hazardous and require proper handling and care. Wear a long-sleeve shirt, long pants, work gloves and safety glasses to keep the chemicals from getting on your skin and in your eyes. Cover any grass, flowers and other landscaping around or below the brick structure you want to clean with a plastic drop cloth or plastic sheeting to keep the chemicals from killing the foliage.
Place the cleaning solution, bucket, water hose or power sprayer, long-handled, stiff fiber scrub brush and any other tools you need for cleaning close to the brick structure you want to clean.
Testing the Chemicals and Solutions
Before starting the brick cleaning process, use a non-metallic chisel or putty knife to remove any large mortar particles that are sticking out of the brick structure, if any are present. Then mix the chemical or solution you want to use according to the manufacturer’s recommendations and proper dilution ratio. Wet the brick surface with water and test the mixture on a small section of bricks to see how the solution is working. If the debris is stubborn and does not come off quickly, consult the manufacturer's recommendations on how to create a stronger dilution ratio.
Spray the brick structure with water from a water hose, pressure washer or power sprayer to remove any loose dust, dirt and debris before cleaning. Pre-rinsing the bricks keeps the cleaning solution from moving debris from the mortar into the brick’s small holes, which can lead to the bricks deteriorating.
If using a pressure washer or power sprayer, do not stand too close to the brick structure when applying water and do not use a pressure setting higher than 700 pounds per square inch (PSI). Using a higher PSI or standing too close to the brick structure can damage the brick surface and its mortar joints.
Always apply the chemical solution to the top of the brick structure instead of the bottom so the mixture runs down and breaks down any debris. Then use a long-handled, stiff fiber scrub brush to vigorously scrub the bricks and mortar. Work quickly and do not let the cleaning mixture dry on the brick structure. Rinse the bricks thoroughly with water after cleaning. Rinsing neutralizes the cleaning chemicals and keeps the mixture from drying on the bricks and leaving streaks.
If you're dispensing the cleaning solution through the pressure sprayer, let the solution sit on the brick surface for 5 minutes then switch the device to water and rinse the structure.
Working in Sections
If cleaning a brick home, wall or other large brick structure, work in sections instead of trying to tackle the entire structure. Apply the cleaning solution to one section, scrub the bricks then rinse the section thoroughly with water.
Homemade Brick Cleaning Solution
If purchasing and mixing a commercial cleaning solution is not possible, mix 1/2 cup of trisodium phosphate (TSP), 1/2 cup laundry detergent and 1 gallon of water in a bucket. Stir the mixture with a long-handled brush, apply the mixture to your brick structure then follow the same cleaning process described in the "Cleaning Process" section. For stubborn stains and debris, fill a non-metallic bucket with 3 gallons of water then slowly pour 1 1/2 quart of muriatic acid into the water. Do not pour the acid first then the water — this can cause a chemical reaction.
TSP or muriatic acid is available at your area hardware and home improvement store.