Costly Blunders That Can Ruin Your Composite Decking

Composite decking has become a popular choice among Australian homeowners and business owners thanks to its stylish appearance, durability and low maintenance requirements. It not only enhances outdoor living areas but also adds long-term value to any property, making it a smart investment.
However, while composite decking is easier to care for than traditional timber, it still requires regular cleaning and proper maintenance to keep it in top condition. Ignoring upkeep can lead to damage, costly repairs and a much shorter lifespan. The good news is that maintaining your composite deck is simple once you know what to avoid.
Below, we explore the most common composite decking maintenance mistakes so you can protect your investment and enjoy your outdoor space for years to come.
1. Cleaning the Surface with Equipment that Can Cause Damage
Scrubbing your deck with abrasive tools like steel wool, scourer pads or stiff brushes can scratch the surface and damage the protective coating. Composite decking has a textured finish designed to resemble timber, and aggressive scrubbing can permanently ruin its appearance.
What to do instead:
Use a soft-bristle brush with warm, soapy water. Cleaning your deck every three to four months using gentle tools is enough to remove dirt, mould and grime without causing damage.
2. Using Caustic Cleaning Products
Bleach and other harsh chemical cleaners can strip away the protective layer of composite decking, causing discolouration, fading and surface breakdown over time.
What to do instead:
Choose pH-neutral or composite-safe cleaning products. We recommend eco-friendly solutions, which are specially formulated for composite boards. When in doubt, check with your decking supplier before using any cleaner.
3. Not Cleaning Up Spilt Foods or Liquids
Leaving food, oil or grease spills on the deck can lead to stubborn stains that penetrate the surface. Over time, this can cause permanent marks and weaken the protective coating.
What to do instead:
Wipe spills immediately and clean the area with a composite decking cleaner to prevent long-term staining.
4. Using a Pressure Washer Incorrectly
High-pressure washing can cause serious damage by etching or gouging the decking surface, especially if the nozzle is held too close or the pressure is set too high.
What to do instead:
If using a pressure washer, keep the setting below 1500 psi and hold the nozzle at least 25 cm from the surface, using a wide fan spray. Otherwise, a standard garden hose is usually sufficient.
5. Allowing Dirt and Debris to Build Up
Leaves, soil and organic matter can trap moisture, leading to mould and mildew growth. Over time, this can stain and damage your deck.
What to do instead:
Sweep your deck weekly and rinse it regularly, especially after storms or windy weather. Preventing buildup is one of the easiest ways to extend your deck’s lifespan.
6. Neglecting the Gaps Between Boards
If dirt builds up between decking boards, it can block drainage and airflow, causing water damage and mould growth beneath the surface.
What to do instead:
Check and clean board gaps every two weeks using a narrow tool like a putty knife or spatula before rinsing the area.
7. Allowing Dirt and Grime to Fester
Everyday debris such as leaves, pollen, pet hair and grass clippings can quickly accumulate and break down into organic matter, which encourages mould.
What to do instead:
Keep your deck clear by sweeping regularly and avoiding outdoor mats that trap moisture.
8. Not Treating Grease Stains Properly
Outdoor dining areas are especially prone to grease stains from barbecues and food spills, which can become difficult to remove if left too long.
What to do instead:
Clean grease stains promptly by:
- Blotting with paper towels
- Rinsing with a garden hose
- Scrubbing gently with warm water and dish detergent
- Rinsing again to remove residue
Repeat if necessary for stubborn stains.









