The short answer
Why Mold Grows on Brick
Mold on exterior brick usually appears in damp, shaded areas where moisture lingers. Brick is porous, so it holds water well, especially during rainy seasons or in humid climates. In a place like Doral, the humid subtropical climate can encourage mold growth on north-facing walls or under eaves.
Before cleaning, check for obvious water problems like leaky gutters or sprinklers hitting the wall. Fixing the moisture source helps prevent mold from returning. If you see water stains on interior walls near the brick, that could mean a bigger issue, and a wall water damage repair service might be needed.
Supplies You Need
Gather a stiff-bristle brush, a bucket, mild detergent or a commercial mold cleaner, water, and a garden hose with a spray nozzle. Avoid using a pressure washer on full power, as it can damage brick mortar and force water deeper into the wall. For safety, wear gloves and eye protection, and consider a respirator mask if you are sensitive to mold spores.
If the mold covers a large area or you have health concerns like asthma, you may want to call local water damage pros. They have the equipment and experience to clean large surfaces safely. Also, if the mold is inside the home or behind the brick, a different approach is needed.
- Stiff-bristle brush or broom
- Mild detergent or mold cleaner
- Bucket and clean water
- Garden hose with spray nozzle
- Gloves and eye protection
- Respirator mask if sensitive
Cleaning Steps
First, dry-brush the brick to remove loose mold and dirt. This reduces the amount of mold you are scrubbing. Then mix your cleaning solution according to the product instructions, or use a few tablespoons of detergent per gallon of water. Apply the solution to a small test area first to make sure it does not discolor the brick.
Scrub the affected spots with your brush, working from the bottom up to avoid streaking. Rinse thoroughly with the hose, keeping the water pressure gentle. Let the wall dry completely. If mold remains, repeat the process or consider a stronger cleaner, but always test it on a hidden spot first.
When to Call the Pros
Some mold situations go beyond a simple scrub. If mold covers a large area, keeps coming back, or you suspect it is inside the wall, professional help is wise. Local water damage pros can assess the extent and clean the brick using specialized methods. They can also identify underlying moisture problems.
If you notice mold inside your home, especially on drywall or wood, that is a different issue. In that case, a mold professional or a water damage restoration service may be needed. For exterior brick, the pros can often clean and treat the surface to slow regrowth, though no method can permanently prevent mold in a humid climate.
Preventing Mold Regrowth
After cleaning, take steps to keep mold away. Trim back shrubs and vines that block sunlight and airflow. Make sure gutters and downspouts direct water away from the walls. Fix any leaks in the roof or sprinkler system that keep the brick wet. If you live in Doral, keeping the wall dry is key to preventing future mold.
You can also apply a water-repellent sealant to the brick, but use caution. Some sealants trap moisture inside the brick, which can cause damage. Consult a professional before applying anything. Regular inspection and quick action when mold appears will make cleaning easier and less frequent.
- Trim vegetation near walls
- Clean gutters and downspouts
- Fix sprinkler overspray
- Inspect for leaks seasonally
- Allow brick to dry between rains
Water damage does not wait
Water keeps spreading into floors and walls, so it is worth acting early. Calls are answered 24/7.
Call Now (305) 614-9705Frequently asked questions
Can I use bleach on brick?
Bleach can kill surface mold, but it does not penetrate porous brick well and may leave a residue. A mild detergent or a commercial mold cleaner is often safer for brick. Always test any cleaner on a small area first.
Will mold on brick harm my health?
Mold can cause allergy symptoms or respiratory irritation, especially for sensitive people. If you feel unwell, see a doctor. Wearing protective gear during cleaning helps. For large mold problems, consider hiring a mold professional.
How do I know if mold is inside the wall?
Musty odors inside your home, water stains on interior walls, or peeling paint near the brick can indicate hidden moisture. If you suspect mold inside, a water damage inspection can help determine the source and extent. Then you can decide on the right repair.