How to Clean Fiber Cement Siding

Unlike other types of siding, fiber cement siding is a low maintenance product you can easily keep in good condition. To clean the siding, you’ll need:

• Sponge
• Soft cloth
• A soft bristle brush
• Garden hose
• Dishwashing or other mild soap
• Tarp
• Pressure washer and soft power brush (if necessary)
• Mildew remover (if necessary)

Tip: Prevent scratching by not using harsh cleaners or abrasive tools when cleaning fiber cement siding.

Although it can take time, cleaning your fiber cement siding is simple.

• Start by using a cloth or long-handled brush to remove any dry dust or debris.
• Use a garden hose to spray your entire house with clear water. Spray until all the siding is clean.

For stained or troublesome spots:

• Mix a mild all-purpose cleaner with water in a bucket. If you’ve got greasy grime, use a degreasing dishwashing liquid.
• Gently wash or lightly scrub the stained siding with a sponge, cloth or soft bristle power brush.
• Rinse off the area.
• Repeat until all the stains are removed.

Tip: Protect plants or shrubbery from suds and runoff with a tarp before cleaning your siding.

If your home is in a high humidity climate, mold and mildew can be a problem. First, remove any loose dirt or dust with a soft brush or cloth. Next, choose one of the following cleaning methods:

• Use a commercial mildew cleaner that’s safe for fiber cement siding. Mix the cleaner with water and spray it on the mold or mildew. Wait for the cleaner to work and then rinse your siding thoroughly. If necessary, spray the area again and repeat. Consult product label for specific directions.
• Household bleach can be used to kill mold and mildew. Use a hand sprayer to apply household bleach to your fiber cement siding. Let the bleach sit a few minutes before rinsing it off with a hose. You may have to repeat this step a few times to completely remove the mildew or mold. (If you prefer, you can use ammonia instead of bleach).

Tip: For very tough stains, consider using a pressure washer with a nozzle for cleaning siding. Make sure to keep the pressure under 1500 psi and spray 12 inches away from the surface to prevent damaging your siding.

• Always test any cleaning solution before applying it across the entire area. Some chemicals may cause your siding to discolor.
• Never use steel wool or other abrasives that can damage and scratch your siding.
• Clean one area at a time. Work from top to bottom to prevent streaking.
• Thoroughly clean your siding regularly to remove dirt and grime. A good rule of thumb is to clean it every six months, once in the spring and the fall.
• Do an annual inspection of the caulking around your siding. Fill any cracks or gaps with a waterproof caulk.
• Wear protective gear such as gloves and safety goggles.