Anything that is exposed to the elements of an outdoor environment will need some attention over time – If not to help maintain its underlying structural integrity, then to keep it looking well cared for. No deck is actually maintenance free, mold, mildew, and dirt attack every deck – wood, metal, plastic or composite, every decking material needs at least a periodic washing.
Composite decking may not require preservative treatments, water sealing, staining or painting, but all decking should be periodically cleaned to maintain aesthetics and reward you years of low maintenance enjoyment. Following are some recommendations in details:
Pressure washer
Pressure washer can be used to clean composite decking. Make sure the pressure washer is no greater than 8Kpa (1200 psi), and you must keep a distance of at least 30cm from the deck surface as this may mark the surface of the deck.

Dirt and debris
Sweep off deck to remove dirt and debris. Routine sweeping with a firm bristled broom is often the most effective way to remove small debris from the deck surface. This also helps keep the spaces between each deck plank open to allow rain water to drain off the deck more easily too. If necessary, you can use warm, soapy water with a scrub brush to gently remove stubborn spots.

Scratches or surface abrasions
Markings of this type should fade with weathering, and the machined finish and embossed pattern on the surface is possible to hide most minor scratches. For larger scratches, you can also remove the scratches with sandpaper, following the grain of the board, please note that over sanding of your deck boards can remove the embossed pattern.
We recommend using a protective mat or pads to prevent contact from items such as furniture legs, BBQ’s stands etc.
Water stains
There will be some water stains on the surface of the newly installed terrace when the water evaporates. It is temporary phenomenon which will disappear in about 1-2 months by itself.
Oil and grease stains
Composite decking is susceptible to stains from food oil, grease and tannin in some vegetation. Best results are achieved if the stain is treated immediately with absorbent cloths, and then apply a commercial deck cleaner or degreaser. Be sure test in an in conspicuous area prior to cleaning the entire deck. Follow up with a general clean with warm and soapy water.
Please note that never use a cleaner that contains bleach as this could permanently discolor the deck surface.
Ice and snow
Use calcium chloride or rock salt to melt the snow and ice from the deck surface.
Mold and mildew
Mold & mildew are commonly found on outdoor building materials. To prevent pollen and debris buildup, periodic cleaning is best. If mold/mildew is present, use warm soapy water made with mild dishwashing detergent and a soft sponge/rag to remove. Thoroughly rinse off with a garden hose when complete.
Commercially available deck cleaners or detergents can be used, make sure that you follow the manufacturer’s recommendations for use and always test the solution in a conspicuous area of your deck first. Follow up with a general clean with warm and soapy water.
Why Sundi Co-extrusion Composite Decking ?

- Sundi Co-extrusion Composite Decking is composed of core and cover. It an advanced tough plastic shield encasing all four sides around its inner WPC core. As a result, they were far more vulnerable to staining and fading.
- The shield and core are extruded together under a very high temperature mold simultaneously, so there are no adhesives or chemicals that are harmful to the environment.
- The wood component within WPC does impact some positive attributes compared to plastic, the inherent problems with wood (moisture sorption and susceptibility to mold and decay) remain. Sundi Co-extrusion Composite Decking is inherently more resistant to damage from moisture, mold and mildew growth, performing better than any traditional composite.
- Sundi Co-extrusion Composite Decking applied hidden fastening system, the hidden fasten clips installation system make easy and quick installation, but more than that, the controlled expansion and contraction clip eliminates warping, or any distorition, providing decking that lasts for years with simple, easy maintenance.
Bottom Line
Maintaining composite decking isn’t difficult. However, choosing the best composite decking material can make a deck easier to take care of than others. Typically, the better-quality composite decking products will also have a longer lifespan.
Sundi Wood Plastic Composite
Zhongshan Sundi New Building Materials Co.,Ltd. is a professional manufacturer specializing in the R&D, production and sales of WPC (Wood Plastic Composite) materials, our products include: composite decking, capped composite decking, WPC Pergola & Gazebo, WPC Railing & Fencing, WPC Wall Cladding, WPC Chairs & Bench, WPC Flower Planter Pots etc.