Concrete walls are known for their texture, durability and lifespan. Although concrete walls usually require minimal maintenance, regular cleaning is necessary to preserve their appearance. Exposure to dust, dirt, insects, weather and grime causes exterior concrete to become dingy over time. Washing concrete walls extends their lifespan and restores their aesthetic appeal. Use basic supplies and techniques to do the job.
Connect a spray nozzle to a garden hose fitting. Rinse the concrete wall with water to wash off loose dirt, dust and grime. Spray from the top of the wall down. Stand on a ladder, if necessary, to reach high areas.
Mix liquid pH-neutral cleaner with warm water in a clean plastic bucket. Use the specific amounts of cleaner and water instructed on the product label.
Fill a second clean plastic bucket with plain water.
Scrub a 3-by 3-foot portion of the wall with the cleaning solution, using a nylon scrub brush. Start at the top of the wall.
Rinse off the cleaning solution and grime with water from the garden hose.
Wash the remaining 3-foot by 3-foot sections of the wall using the same technique. Frequently rinse the scrub brush in the plain water. Occasionally prepare fresh cleaning solution to avoid getting the wall dirty again. Work across and down the wall until the concrete is completely clean. Stand on the ladder to access hard-to-reach areas, if necessary.
Rinse the entire wall with water to wash away any remaining solution.
Allow the concrete wall to air dry.
You can substitute a commercial concrete cleaner for the pH-neutral cleaner. Use the concrete cleaning according to the manufacturer's instructions. Remove stubborn stains with undiluted white vinegar.