Is It Safe to Pressure Wash Composite Decks? Here’s What You Need to Know
Composite decking is prized for its low maintenance, durability, and resistance to rot and splintering—but that doesn’t mean it never needs a good cleaning. If you’re considering pressure washing your composite deck, follow these guidelines to ensure you remove dirt and mildew without damaging the surface.
Why Composite Decks Still Need Cleaning
Dirt and pollen buildup can leave a dull film on the boards.
Mold and mildew thrive in shaded, damp areas, leading to slippery spots.
Weathering over seasons can hide stains that diminish your deck’s appearance.
The Risks of High-Pressure Washing
Lifting and gouging: Too much pressure (above 1,500 psi) can erode the deck’s protective shell, exposing the inner material.
Board separation: Forceful water jets aimed at seams or edges can force water underneath, leading to trapped moisture.
Color fading: Aggressive cleaning can dull or bleach the deck’s pigment.
Best Practices for Safe Pressure Washing
Use a Low-Pressure Nozzle (25° or Wider)
Set your washer to 500–600 psi. This gently lifts grime without harming the board surface.
Keep the Wand Moving
Hold the nozzle about 12–18 inches from the deck and spray in smooth, overlapping strokes. Don’t linger in one spot.
Test in an Inconspicuous Area
Before tackling the entire deck, try a quick wash on a hidden corner or behind furniture to ensure no etching occurs.
Combine with a Deck-Safe Cleaner
Apply a manufacturer-approved composite deck cleaner, let it dwell per instructions, then rinse. These cleaners help loosen dirt and mildew so you can use even gentler pressure.
Mind the Direction of the Grain
Spray along the length of the boards, not across them, to prevent splintering or edge damage.
Alternative: Soft-Wash Systems
If you’re concerned about pressure washing, consider a soft-wash approach. It relies on low‐pressure sprayers and biodegradable detergents to dissolve stains, then a gentle rinse to clear residue. This method virtually eliminates risk of surface damage while providing professional-grade results.
Bottom Line
Yes—you can pressure wash a composite deck safely, but only if you use the right pressure, nozzle, and technique. When in doubt, lean on soft‐wash methods or call in professionals like TLC: Making It Easy. We have the expertise and equipment to restore your composite deck’s beauty without voiding warranties or risking damage.
Ready for a spotless, worry-free deck cleaning? Contact TLC: Making It Easy today for a no-obligation estimate!