To clean composite decking in Jacksonville's humid, salty climate, wash it with warm soapy water and a soft-bristle brush at least twice a year, then rinse it off completely. Our coastal humidity helps mold, mildew, and salt film build up fast, so regular rinsing and the right cleaner matter more here than in dry climates.
- Use warm water with mild dish soap and a soft-bristle brush; rinse with a garden hose, not a high-pressure tip that can damage the board surface.
- For mold and mildew (common in NE Florida shade and humidity), use a composite-safe deck cleaner and follow the board maker's directions, like Trex or MoistureShield.
- Rinse salt and pollen off decks near the coast more often, and clean up grease or food spills right away before they set.
To clean composite decking, sweep off the dirt, then wash the boards with warm water, mild soap, and a soft-bristle brush. Rinse well with a garden hose. Do this two or three times a year and your deck will stay looking great. That is the short answer. In Florida, the trick is staying ahead of mold and salt, which we will walk through below.
We are Jacksonville Deck Builders, a Coastal Outdoor Construction brand. We have built decks across Northeast Florida since 2013, with more than 500 decks done and a 4.9-star rating on 70 Google reviews. We build new decks and full deck replacements. We do not offer a cleaning or repair service, but we know these boards inside and out. Here is exactly how to keep yours clean.
Why Florida Is Hard on Composite Decks
Composite decking is low-maintenance, not no-maintenance. And Florida tests it harder than most places.
Our weather brings three things that build up on a deck:
- Humidity and shade grow mold and mildew, especially in spots that stay damp.
- Salt air and salt spray near the coast leave a film on the boards. This matters a lot in Atlantic Beach, Ponte Vedra, and any home close to the water.
- Pollen and tree debris coat everything in spring and fall, then trap moisture.
None of this hurts a quality composite board. Boards like Trex and MoistureShield are built to shrug it off. But the dirt and mold still sit on the surface, and that is what makes a deck look tired. The good news is it cleans off easily.
How to Clean Composite Decking, Step by Step
You do not need fancy gear. A bucket, a brush, and a hose handle almost every job.
1. Clear the deck
Move the furniture, the grill, and the planters off to the side. Sweep the whole deck with a stiff broom. Get into the grooves between boards where leaves and pollen like to hide.
2. Rinse it down
Spray the deck with your garden hose to knock off loose dirt before you scrub. This keeps grit from grinding into the surface.
3. Wash with soap and water
Mix warm water with a little mild dish soap in a bucket. Work in small sections. Scrub along the length of the board with a soft-bristle brush. Always brush the same direction as the wood-grain pattern, not across it.
4. Rinse again
Rinse each section well before the soap dries. Soap left to dry leaves a haze. Rinse from the house outward so the dirty water runs off the deck, not back across clean boards.
5. Let it dry
Let the deck air dry before you move the furniture back. That is it.
Do this in spring and again in fall, and add a quick wash mid-summer if you are near the coast and getting salt buildup.
How to Get Rid of Mold and Mildew
Green or black spots are usually mold or mildew sitting on top of the board. They love shady, damp corners. We see this often on north-facing decks and decks tucked under big oaks in Mandarin and Riverside.
To clean them off:
- Use a composite deck cleaner made for mold, or a mix of warm water and white vinegar.
- Let it sit on the spot for a few minutes so it can work.
- Scrub gently with a soft brush.
- Rinse fully with the hose.
Always check the label on any cleaner against your decking brand's care guide first. Some products are not approved for certain boards, and using the wrong one can void the warranty.
Thinking about a new composite deck, or replacing one that is past its prime? Jacksonville Deck Builders builds across Duval, St. Johns, Nassau, and Clay counties. Call (904) 944-9253 for a free in-home estimate, and demo and haul-away of your old deck is free with a replacement.
The Pressure Washer Question
You can use a pressure washer on most composite decks, but you have to be careful. Too much pressure can damage the surface and, again, can void your warranty.
If you use one, keep it gentle:
- Stay at or below the pressure your decking brand recommends.
- Use a wide fan tip, never a narrow jet.
- Keep the nozzle moving and hold it well back from the boards.
- Spray with the grain, never straight down hard in one spot.
Honestly, for most homeowners, a hose and a brush are safer and work just fine. Save the pressure washer for stubborn jobs only.
What to Avoid
A few things will do more harm than good on composite boards:
- Bleach in heavy doses or harsh chemicals. They can fade or streak the color.
- Metal scrapers and wire brushes. They scratch the surface.
- Letting grease sit. Wipe up grill grease and food spills quickly so they do not stain.
- Rubber mats and welcome mats left in one place. They trap moisture and can leave marks. Move them now and then.
Composite vs. Wood: Less Cleaning, More Time Outside
One big reason homeowners here choose composite is the easy upkeep. A pressure-treated pine deck needs sanding, staining, and sealing every year or two to survive Florida's sun and rain. A composite deck just needs a wash. No staining, no sealing, ever.
If you are weighing your options, you can read more about your choices on our composite decking in Jacksonville page, where we cover Trex and MoistureShield, the brands we are authorized to install. Composite decks run roughly $28 to $42 per square foot installed, while pressure-treated pine runs about $20 to $30. AZEK PVC decking and Ipe hardwood are our premium material and are priced at $20–30 per sq ft, below composite. These are ballpark numbers, and a free in-home estimate gives you a real estimate for your project.
Composite is also a smart pick around water. If you have a pool, the boards stay cooler and cleaner than you might expect, and they handle splash and chlorine well. You can see how we approach pool decks in Jacksonville if that is on your wish list. And because every deck we build is engineered for Florida's 130 to 150 mph wind code, you get a deck that lasts and cleans up easily for years.
A Simple Florida Cleaning Schedule
- Spring: Full wash to clear off winter grime and pollen.
- Summer: Quick rinse, plus an extra wash if you are near the coast.
- Fall: Full wash to clear leaves and prep for the cooler months.
- Anytime: Wipe spills fast and knock down any mold spots as you spot them.
Stick to that, and your composite deck will look almost new for a very long time.
Ready for a New Deck?
Cleaning keeps a good deck looking good. But if your deck is worn out, sagging, or just not what you want anymore, a fresh composite deck is the better move. As a FL-licensed, fully insured general contractor, Jacksonville Deck Builders handles the whole job, from design to the last board, across Duval, St. Johns, Nassau, and Clay counties. Call us at (904) 944-9253 for your free in-home estimate.