How to Clean Your James Hardie Siding

One of the best parts of James Hardie siding is just how easy it is to keep it looking beautiful! With a little regular maintenance and armed with the knowledge to take care of specific contaminants, your fiber cement siding will look great for years to come. If you’re searching for a guide on how to clean Hardie board siding, we’ve got your back. 

Regular Maintenance: Every 6 to 12 Months

Do you want to keep your James Hardie fiber cement siding looking as good as the day it was first installed? With a few common tools and simple solutions, cleaning the mold, mildew, dirt, and oil off your home’s siding will be easy. 

You Will Need

  • A garden hose with low-pressure water spray
  • A soft, medium bristle brush OR a wet cloth
  • A mild detergent

All you need to do to keep your siding sparkling is a little care every six to twelve months. Starting from the top and working your way down, James Hardie recommends rinsing your siding with a low-pressure spray from your garden hose. Afterward, you can spot clean any unsightly marks with a soft, medium bristle brush or a wet cloth, working in small sections at a time. If a stain is particularly stubborn, you may want to use a mild detergent to wipe it away.

Note: According to the manufacturer, high-pressure water blast and sandblasting may damage the surface of your fiber cement product. If you were wondering how to pressure wash and clean hardie board, the answer is don’t. Acid washing can also cause damage and is best avoided.

How to Address Spots on Your Siding from Different Contaminants

Sometimes, a spot on your James Hardie fiber cement siding may require a little extra effort to remove. Here’s are the best tools and solutions to address dirt, grease, and mildew on your home’s exterior. You can also check out some of our other videos to learn more about your Hardie siding.

Remove Dirt from Siding

How do you clean painted hardie board? If a rough Pennsylvania wind spatters your siding with dirt, simply brush away the debris with a soft brush; poly, chip, and horsehair work best. Then, rinse with low pressure from your garden hose. Done!

Tackle Siding Oil Stains

Oily fingers can leave unattractive marks on your siding. To remove, wipe away the stains with a soft cloth dipped in soapy water. Make sure to keep rinsing the cloth as you go! Once you’ve removed the stain entirely, rinse your siding clean with a low-pressure stream from your garden hose.

Clean Mold and Mildew Off Siding

To address mold and mildew, you’ll need a soft cloth or a sponge, and a mildew cleaner (Jomax®, Mildew Check®, Mold Armor® work perfectly!) Carefully read the instructions on your siding cleaner, and lightly scrub the affected area with your cloth or sponge. Make sure to use enough siding milder remover to cover all problem areas.

Use your garden hose to gently rinse the area. You’re done!