StateLine Exteriors | Kansas City

Maintain Your Hardie Siding and Protect Your Warranty with These Tips

If you recently installed beautiful, long-lasting James Hardie fiber cement siding, you’re likely wondering what you can do to maintain your home’s pristine condition for as long as possible. 

Aside from your home’s appearance, proper care is essential to maintain your siding’s integrity and protect your industry-leading warranty.  

Thankfully, it’s easy to keep your Hardie siding in tip-top shape. Follow this expert advice to keep your boards clean and well-maintained.

What Does My James Hardie Warranty Cover?

Since Hardie siding is exceptionally long-lasting and weather-resistant, it is backed with a 30-year limited warranty. However, your siding must be adequately cared for to preserve this industry-leading guarantee.

Among other conditions, your limited warranty does not cover defects or damage from the following: 

  • Peeling of any third-party paints, stains, or coatings 
  • Growth of mold, mildew, fungi, bacteria, or other organisms 
  • Lack of proper maintenance 
  • Neglect, abuse, or misuse 
  • Damage resulting from water infiltration 

How to Clean Your Fiber Cement Siding

Here are some cleaning methods you can use to keep your fiber cement siding looking beautiful that will also protect your James Hardie warranty.

Dirt and Dust

Your siding will naturally collect dust and debris. You should routinely wash your siding every 6 to 12 months to prevent dirt build-up. To remove grime:

  1. Rinse your home’s exterior with a garden hose (starting from the top to prevent streaking).
  2. Gently clean the siding with a soft brush or rag using a side-to-side motion.

Mold and Mildew

Mold and mildew growth is caused by excess moisture on your home’s exterior and is especially common in damp, humid environments. To remove the growth:

  1. Spray a mildew cleaner (safe for siding) to the affected area.
  2. Allow the cleaner to sit for the length of time it recommends on the instructions.
  3. Use a soft sponge to loosen the mold and mildew on the siding.
  4. Rinse the remnants off with a garden hose.

Grease and Stains

Grease, oil, and other pesky stains require extra care to eliminate. To remove stains:

  1. Apply gentle dish soap to a wet rag.
  2. Scrub the affected area(s) and use a garden hose to rinse them.

What Shouldn’t I Use to Clean My James Hardie Siding?

To protect your hardie board siding from damage when you’re cleaning, steer clear from:

  • Harsh chemical cleaners
  • Metal brushes or abrasive rags
  • Power washers

If you decide to use a power washer to clean your siding, you should keep the pressure below 1500 psi and maintain a distance of six feet from your home’s exterior.

Maintenance Tips to Prevent Siding Damage

One of the best ways to keep your siding in excellent condition is to perform routine maintenance that prevents damage not covered by your warranty, like moisture intrusion. 

Your preventative maintenance checklist should include:

  • Cleaning leaves, twigs, and other debris from your gutters and pipes
  • Trimming trees, bushes, and shrubs away from your home’s siding
  • Adjusting your sprinkler system to spray away from your home
  • Using sand or gravel, rather than deicing salts, on snowy surfaces

How to Correctly Repair Damaged Siding

When cleaning your siding, it’s common to notice a spot that needs patching or a board that needs a touch-up. Since your warranty doesn’t cover peeling of third-party paints, stains, or coatings, it’s vital to ensure you complete your re-caulking and painting correctly.

ColorPlus Technology

If you installed fiber cement siding with ColorPlus® Technology, your boards also came with an additional 15-year limited warranty. You can apply ColorPlus Touch-Up for nicks, scrapes, and small holes that occur over time.

However, if the affected area is larger than a dime, James Hardie recommends replacing the damaged siding with a new panel.

Primed for Paint

If your siding boards were primed for paint, follow the original paint manufacturer’s recommendations for paint reapplication. As a general rule of thumb, James Hardie recommends applying a quality 100% acrylic paint to clean siding.


Fill dents, chips, and cracks with cementitious patching compound (acrylic mortar patch). Refer to the manufacturer’s instructions, and confirm the product is compatible with fiber cement.


Caulk protects your home from water damage and may need to be reapplied to flashings, penetrations, and trim connections over time. When re-caulking your home, use a permanently flexible caulk that complies with ASTM C834 or better. Follow the manufacturer’s application instructions.

Want to know more about James Hardie Siding? Our “Ultimate Hardie Siding Guide” has the info you need. Read the Guide

Learn More about Your James Hardie Siding from a Reliable Local Contractor

It’s easy to keep your siding looking beautiful for decades. All you need are the correct tools and resources, along with a consistent cleaning and maintenance schedule. 

As Kansas City’s award-winning James Hardie contractor, our team at StateLine Exteriors wants to equip you with the knowledge you need to properly care for your high-performance fiber cement siding.

Learn more about the fantastic benefits and hassle-free maintenance that James Hardie siding offers for you and your family!

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