Fiber Cement Siding Maintenance

Follow these recommendations for fiber cement siding maintenance to help your home’s siding stay beautiful for years to come.

Please follow these recommendations on caring for your James Hardie products. Damage to siding and trim arising from improper cleaning or maintenance may not be covered by the James Hardie warranty.

Exterior House Washing Recommendations for Fiber Cement Siding and Trim


Follow these recommendations to clean the exterior of your home and to help maintain the beauty and value of your James Hardie siding.
 
  • Wash down the exterior surfaces every 6 to 12 months with a garden hose to remove dirt and debris, gently clean your siding with a soft brush or wet soft cloth in a side to side motion in the direction of the plank siding.
    ​NOTE: Clean by working small sections at a time, starting from the top down to prevent dripping or streaking onto the cleaned area.
     
  • A low pressure water spray* and a soft medium bristle (non-metal) siding cleaning brush is most suitable for cleaning fiber cement products.
    NOTE: Acid and high pressure washing can damage the fiber cement surface and is not recommended.
     
  • Clean James Hardie ColorPlus® products by using water and a soft brush or cloth. For stubborn dirt or stains, a mild detergent and a soft brush may be used.
    NOTE: For paint applied in the field, refer to the paint manufacturer for washing and maintenance requirements.
     

Pictured clockwise from top left: Soft All Paint Brush, Horsehair Brush, Siding Brush, Chip Brush,

*Pressure Washer Warning:
Extra care should be taken when cleaning your siding and trim using a pressure washer. To minimize the chance of damaging your siding and trim use a wide fan tip, keep a minimum of 6 feet from the wall, and keep the pressure below 1500 psi.

General Fiber Cement Siding Maintenance

Maintaining the exterior of your home helps prevent water intrusion and is an important part of sustaining the beauty and value of your home. The extent and nature of maintenance will depend on the design of your house, its geographic location, the amount of weather and sun exposure, and the landscaping near your house. As a guide, it is recommended that normal fiber cement maintenance tasks and care include:
 
  • Installing gutters and downspouts on your home—if they are not already present when you purchased the home.
     
  • Cleaning out your gutters, blocked pipes, and overflows of any debris, leaves, twigs and dirt.
     
  • Keeping vegetation such as shrubs, bushes, and small trees trimmed back and away from the home and siding.
     
  • Adjusting sprinkler systems so they do not excessively spray on siding or continuously soak the ground near your house.
     
  • Avoiding direct contact with deicing salts, as these salts may prematurely damage the finished look of the siding. We recommend the use of sand or gravel to manage snowy or icy surfaces near siding.
     
  • Ensuring required external ground clearances (typically 6 in.) and drainage slopes are maintained. NOTE: Do not in fill landscaping up to the siding.

Re-Painting Siding

ColorPlus® Products
  • ColorPlus® Touch-up Kits can be used to cover nicks, scrapes and nail holes that may occur over time.
     
  • If the touch up area is larger than the size of a dime, the use of ColorPlus® Touch-up Kit is NOT recommended. It is advised to replace the damage siding with a new section of ColorPlus® siding.
     


Primed Products
  • If your James Hardie siding was originally painted after it was installed on your home, then check the original paint manufacturer’s recommendations for reapplication of paint.
    NOTE: Do not use stains or oil-based/alkyd paints on James Hardie products. For additional information on finishing James Hardie products, download Technical Bulletin #22 from here.
     
CM_OSI_QUAD_Sealant_15pct.jpg

Fiber Cement Siding Repair or Patching
  • Re-applying caulking when it has begun to show signs of wear can help keep moisture from getting into the wall cavity. These areas include, but not limited to, penetrations, flashings, plank and trim connections, and in some cases, between plank joints.
    NOTE: James Hardie recommends the use of caulks and sealants that remain permanently flexible. Look for the words “permanently flexible” written clearly on the label or in the accompanying literature. For best results, use an Elastomeric Joint Sealant complying with ASTM C920 Grade NS, Class 25 or higher, or a Latex Joint Sealant complying with ASTM C834. Caulking/sealant must be applied in accordance with the caulking/sealant manufacturer’s written instructions or ASTM C1193.
     
  • Dents, chips, cracks and other minor surface damage in James Hardie siding and trim products can be filled with cementitious patching compound. Refer to manufacturer’s recommendations for products that are compatible with fiber cement.