The secret to pressure washing for composite decking is using the right method, not the most pressure. In Washington, we match the cleaner and pressure to the surface so it comes out clean without damage. For composite decking, that means low-pressure wash.
The right method for the job
Cleaning solution: A composite deck cleaner recommended by the decking maker.
Cleaning composite decking safely
Composite decking doesn't need staining, but it does grow mold and mildew, especially in shade and between boards. Most manufacturers recommend gentle cleaning, and some limit the pressure that can be used without affecting the warranty.
Avoid: High pressure and narrow tips, which can scar the surface and may void the warranty.
How often: Every year, more often in shade.
Signs you need pressure washing for composite decking
- Driveway or walkways look dark, gray or streaky
- Green or black growth in shaded areas and along edges
- Slippery surfaces after rain
- Oil, rust or tire marks you can't scrub out
- You're getting ready to sell, seal or paint
What causes the dirt and stains
- Dirt and pollen that settle into the pores of concrete
- Mold, mildew and algae in damp, shaded spots
- Oil and fluid drips from vehicles
- Rust from sprinklers, furniture and fertilizer
- Tire marks and general foot traffic
What you can do yourself
- Sweep off leaves and loose debris so they don't stain
- Blot fresh oil drips with cat litter or an absorbent right away
- Point sprinklers away from walls and walkways to cut down on rust and hard-water stains
- Rinse pollen off with a garden hose during heavy pollen season
Not sure what you're looking at? The free stain identifier and safe pressure guide explain each stain and surface.
Common mistakes to avoid
- Etched lines and 'zebra stripes' from holding a narrow tip too close
- Water forced into window frames, door sills and siding laps
- Damaged plants and lawns from chemical runoff
- Injuries: a zero-degree tip can cut skin, and wet surfaces are slippery
Our process for pressure washing for composite decking
- Walk the property and note surfaces, stains and anything fragile
- Protect plants, outlets, lights and doors, and move small items
- Pre-treat organic growth and degrease oil spots
- Clean with the right pressure and a surface cleaner for even results
- Rinse, post-treat to slow regrowth, and walk the job with you
Typical pressure washing for composite decking prices
What moves the price:
- Size: square footage of siding, roof or flatwork
- Condition: heavy growth, old stains and peeling finishes take longer
- Access: number of stories, roof pitch, slopes and how close we can park
- Add-ons: sealing, gutter brightening and other services done in the same trip
These are typical U.S. ranges, not a quote. You get an exact price before any work starts. For a quick estimate, try the pressure washing cost calculator.
Other services for composite decking
Serving Washington and nearby towns
Moss and algae make Washington driveways, walkways and patios slippery for much of the year. Cleaning with a surface cleaner and post-treating keeps them safer for longer.
We cover 310 cities and towns across Washington. Find pressure washing for composite decking in your city:
Pressure Washing for Composite Decking: frequently asked questions
How much does pressure washing for composite decking cost in Washington?
Pressure Washing for Composite Decking typically costs $150-$600 for a typical home's driveway, walkways and patio, and usually takes 1-4 hours. The exact price depends on the size and condition, and you get it before any work starts. Call (555) 010-0000 for a free quote.
Do you use high pressure for pressure washing for composite decking?
For composite decking: low pressure, often under 1,500 PSI with a wide fan tip, held well back; check your decking brand's care guide. What we avoid: high pressure and narrow tips, which can scar the surface and may void the warranty. The cleaning solution does most of the work, followed by a gentle rinse.
Is pressure washing for composite decking safe for my plants and pets?
We pre-wet plants and lawns, keep cleaning solutions diluted to what the surface needs, and rinse landscaping again when we finish. Keep pets and children inside until surfaces are rinsed and dry.
How often should I schedule pressure washing for composite decking?
Every year, more often in shade. Shade, nearby trees, humidity and heavy traffic mean more frequent cleaning; sunny, dry spots can go longer. Our free cleaning frequency tool gives a recommendation for your climate.
What if it rains on the day?
Light rain doesn't stop most washing, but heavy rain, high wind, lightning and freezing temperatures do. If the weather isn't right, we reschedule at no charge. Our work is backed by a satisfaction guarantee.