How Should I Maintain My Composite Deck?

When composite decking was first introduced it was often promoted as being a "no maintenance" product.  This resulted in many disappointed early adopters as they found out the hard way that staining, mildew, and even mould (specifically with sawdust based composite) was the net result of performing little to no maintenance.
Since those early days of composite decking many improvements in how it's manufactured, specifically around the areas of outer shell capping (provides a lower maintenance wrap around the composite core), and the consistency of the composite itself (removing sawdust for example) have eliminated a lot of the pitfalls of poor maintenance.  The product is also now marketed as being "low maintenance" versus "no maintenance", this has better aligned expectations with the intended performance of the product.
Even with the product improvements I mentioned, it's still important (and manufacturer recommended) to perform regular maintenance on a composite deck.  Now don't get too nervous, maintaining a composite deck is still much easier (and less costly) than a natural wood one.  No sanding and staining involved!! 

Periodic Cleaning:

• Power wash using dish soap detergent.  Be sure to not exceed 1700 psi and use the fan tip nozzle setting.

• Spray in the direction of the brush/grain pattern to avoid damaging the composite decking.

• Be sure to operate the power washer per the manufacturers recommendation.       

Dealing with Dirt, Grime & Mildew:

• Even if your composite decking appears clean, it is important to periodically hose it off with water (or use a power washer on a low setting).

• Doing so prevents the buildup of pollen and debris.  Mildew may occur when pollen and/or dirt are present.  Mildew requires a "food source" to grow, which can be grass, pollen, dirt, debris, wood (or wood resins). 

• The best way to combat mildew is to maintain a clean and dry surface.

Spots, Stains & Scratches:

• Most stains can be removed using dish soap and water.

• If the stains have set, carefully use a wire brush to remove them.  Be sure to brush with the grain.

• This technique may cause the freshly cleaned section to be lighter than other areas of the deck.  It should blend to the rest of the deck after 6 to 10 weeks of sun exposure.

Choosing composite decking that contains mostly recycled materials, and doesn't use sawdust, or wood resins as a binder, is the best way to ensure that mould doesn't develop inside the decking itself.  No matter how much surface maintenance is performed, wood based composites are susceptible to internal mould growth.  The TruNorth Enviroboard and Accuspan lines, contain 95% recycled materials (with rice hulls), this all but eliminates any organic materials, which are the building blocks for mould.  Check out the full TruNorth line by clicking here.     
**Note:  These suggestions are meant to provide a general overview on how to maintain a composite deck.  Please refer to the specific cleaning instructions provided by the manufacturer of your composite deck.**