How to Clean Bricks

Two Methods:Pressure washingHand and hose

Brick are one of the most durable and beautiful facades in building construction, but even they need occasional attention. If your brick are beginning to get moldy or stained from water splash, with a little work and common chemicals, they can look almost new. Bricks are hard objects.

Method 1
Pressure washing

Rent a pressure washer for very stubborn soil or stains. Be careful not to "etch" the masonry joints or brick when using this method.

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    Get all your materials together for the job prior to beginning. You'll need a water bucket, bleach, scrub brush, water hose or pressure washer.
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    Mix a solution 1/2 to 1/2 of bleach and water.
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    Spray on with bottle applicator or with brush.
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    Soak brick in small manageable areas.
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    Scrub before it dries.
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    Rinse. It should be clean now.

Method 2
Hand and hose

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    Choose the type of stain or dirt you are dealing with. Mold, mildew, or algae require different methods and chemicals than do rust stains or cement and mortar smears.
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    Clean your brick with a solution of chlorine bleach if you have mildew or mold problems.
    • Mix chlorine bleach with water in a large bucket, using equal proportions.
    • Pour the solution into a pump type garden sprayer, and pump it up.
    • Wet a section of wall (or patio, if cleaning pavers) with a water hose.
    • Spray the bleach solution on the surface, beginning at the top, on a wall, soaking it thoroughly.
    • Allow the bleach solution to react with the stains for a few minutes, but do not leave it long enough for it to begin to dry.
    • Rinse a small section of wall to see if the solution is having the desired effect.
    • For serious stains, scrub the wall with pure bleach, using an acid brush on a broom-type handle.
    • Rinse the wall thoroughly with water. Be careful not to let the bleach solution dry on the wall before rinsing.
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    Use an acid solution to clean mortar stains, rust from irrigation well water, or soil that a bleach solution doesn't clean to your satisfaction.
    • Buy an acid based masonry detergent or muriatic acid available at home improvement stores, hardware stores, or building supply centers. (Review the Warnings below before purchasing or using any muriatic acid solution.)
    • Fill a plastic bucket 2/3 full of clean water. Add acid at a proportion of about 1 part acid to 3 parts water, but do not fill the bucket too full, as you will not want this solution to splash out accidentally.
    • Wet the wall or other surface with a garden hose.
    • Brush the diluted acid solution on the wall, scrubbing as you apply it with an acid brush.
    • After applying and scrubbing with the acid solution, allow the acid to work for 10 to 15 minutes, being careful not to let the wall dry out.
    • After giving the solution time to work, rinse thoroughly with copious amounts of water.
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    Rinse all surfaces exposed to either of the above mentioned cleaning solutions, using plenty of water to dilute them to prevent damage to surfaces or plants.
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    Consider sealing the brick to prevent future staining or soiling. Use a siloxane or silicone sealant, applied following the manufacturer's directions.


  • Work when there is minimal wind to prevent spray from going where you do not want it to.
  • Wear old clothing, rubber gloves, and goggles when applying the cleaning solutions mentioned above.
  • Work on shaded areas, or shaded sides of the project when possible.


  • Avoid contact with skin when using even dilute solutions of acid or bleach.
  • Never mix acid and bleach when cleaning.
  • Do not breath concentrated vapors from these cleaning solutions.
  • Wear safety glasses
  • The Brick Industry Association strongly recommends against the use of unbuffered muriatic acid because it tends to cause further stains in some types of brick, and because it can damage mortar joints. [1] It is also extremely difficult to completely remove from masonry and can cause problems years later. Adding water to muriatic acid does not solve this problem. Masonry detergents, however, even when they use acid, include chemical buffering agents “that make them safer, easier to use properly and more environmentally responsible.” [2]

Things You'll Need

  • Acid brushes with handles.
  • Rubber gloves.
  • Hydrochloric acid (HCl)
  • Chlorine bleach.
  • A garden hose.
  • Safety Glasses
  • Optional: pressure washer.

Article Info

Categories: Home Improvements and Repairs