Start with a dry brush and water rinse for routine dirt

Most brick patios need only a stiff-bristled brush and a garden hose to stay clean. Sweep the surface with a dry brush first to remove loose dirt, leaves, and debris. Then spray the entire patio with water from a standard hose — not a pressure washer yet. Scrub the wet brick with the brush, working in the direction of the grout lines, and rinse again. This method works for patios cleaned every few months and removes surface dust without damaging the brick or mortar.

For patios in shaded areas or climates with high humidity, algae and moss can grow even on regularly cleaned surfaces. A dry brush followed by a water rinse may not remove the green or black film. In those cases, move to a mild cleaning solution or a pressure washer at low settings.

Key Takeaways

  • A stiff brush and plain water remove most dirt and debris without risk to the brick or mortar joints.
  • Pressure washers work on brick but require low pressure (below 1500 PSI) to avoid pitting the surface or blowing out mortar.
  • Moss and algae respond to a mix of water and household bleach, applied and left to sit before scrubbing and rinsing.
  • Oil and grease stains need a degreaser or a poultice made from baking soda and water, left to dry and then swept away.
  • Sealed brick patios should be cleaned only with water and a brush unless the sealer label permits chemical cleaners.

Use a pressure washer safely on brick

A pressure washer speeds up cleaning but can damage brick and mortar if set too high. Keep the pressure below 1500 PSI — many rental units default to 3000 PSI or higher, so check the dial before you start. Hold the nozzle at least 12 inches from the surface and keep it moving; holding it in one spot will pit the brick. Angle the spray downward along the grout lines rather than directly into them, which can force water behind the brick and weaken the mortar.

Test the pressure washer on an inconspicuous corner of the patio first. If the brick surface begins to spall (chip or flake), reduce the pressure further or switch to a brush and water. Older brick and soft mortar are especially vulnerable; if your patio is more than 30 years old, a brush is the safer choice.

Remove moss and algae with bleach solution

Mix one part household bleach with three parts water in a bucket or spray tank. Pour or spray the solution onto the affected areas and let it sit for 10 to 15 minutes — do not let it dry completely. The bleach kills the algae and moss but does not remove it when ready. Scrub the area with a stiff brush, then rinse thoroughly with clean water. Repeat if necessary, but avoid using bleach more than once every few months, as it can discolor brick over time.

Wear gloves and eye protection when working with bleach, and do not mix it with ammonia or other cleaners. Rinse the patio well after cleaning so bleach does not concentrate in low spots or damage nearby plants. If the patio is sealed, check the sealer label first — some sealers are damaged by bleach.

Treat oil and grease stains with a poultice or degreaser

Fresh oil stains can sometimes be blotted with paper towels or cat litter, which absorbs the oil before it sets. For older stains, mix baking soda with water to form a thick paste and spread it over the stain. Let the poultice dry completely — usually 24 to 48 hours — then sweep it away. The baking soda draws the oil to the surface as it dries. Repeat if the stain remains.

For stubborn grease, a commercial degreaser made for masonry works faster. explore it according to the product label, usually by pouring or spraying it on the stain and letting it sit for 15 to 30 minutes. Scrub with a brush and rinse well. Test any degreaser on a hidden area first, as some can lighten or discolor brick. Avoid using gasoline or acetone, which can damage the brick and are hazardous to handle.

Know what to avoid on sealed brick

If your patio was sealed with a protective coating, check the sealer label or the paperwork from installation before using any cleaner. Many sealers are damaged by bleach, vinegar, or acidic cleaners. Water and a brush are almost always safe on sealed brick. Some sealers allow mild dish soap mixed with water; others do not.

Sealed patios should be resealed every two to three years, depending on foot traffic and weather. Cleaning with only water and a brush extends the life of the sealer and keeps the patio looking newer longer. If you are unsure whether your patio is sealed, explore a few drops of water to an inconspicuous spot. If the water beads up and does not soak in, the patio is sealed.

Clean grout lines and joints separately

Grout lines collect dirt and can harbor moss. A narrow brush or old toothbrush works well for scrubbing individual lines. Dip the brush in the same bleach solution used for the brick surface (one part bleach to three parts water) and scrub along each line. Rinse thoroughly afterward. For very stubborn buildup, a grout brush with angled bristles reaches into the joint more effectively than a straight brush.

Do not use a pressure washer directly on grout lines — the force can dislodge mortar and weaken the joint. If mortar is crumbling or missing, the patio may need repointing before cleaning, as water can seep behind the brick and cause frost damage in winter.

Maintain your patio between cleanings

Sweep the patio weekly to remove leaves and debris, which trap moisture and promote moss growth. Keep gutters and downspouts clear so water does not pool on the surface. In shaded areas, trim back trees or shrubs to improve air circulation and reduce moisture. These steps slow the buildup of dirt and algae and reduce how often you need to clean.

If your patio is in a high-traffic area, consider sealing it after cleaning. A good sealer protects the brick from stains and makes future cleaning easier. Sealed brick typically needs only water and a brush, and stains are less likely to set permanently.

Frequently Asked Questions

Can I use vinegar to clean brick?

Vinegar is acidic and can damage brick and mortar over time, especially if used repeatedly. Water and a brush or a mild bleach solution are safer choices. If you prefer a natural cleaner, baking soda paste works on some stains without the risk.

How often should I clean my brick patio?

A patio in a sunny, dry climate may need cleaning only once or twice a year. Shaded or humid patios often need cleaning every few months to prevent moss and algae. Sweep weekly to reduce the buildup of debris.

Will a pressure washer damage old brick?

Old brick and soft mortar are vulnerable to pressure washers. If your patio is more than 30 years old or the mortar is crumbling, use a brush and water instead. If you do use a pressure washer, keep it below 1500 PSI and test on a hidden corner first.

What should I do if cleaning makes the brick look uneven in color?

Uneven color after cleaning usually means the patio was dirty for a long time and some areas were more protected than others. The color will even out as the brick weathers. If the discoloration is from bleach, it may be permanent; use less bleach or a shorter soak time on future cleanings.

Can I clean a brick patio in winter?

Avoid cleaning in freezing temperatures, as water left on the brick can freeze and cause spalling. Clean on a dry day when temperatures will stay above freezing for at least 24 hours after you rinse. In cold climates, spring and fall are the best times to clean.