Exterior & outdoor cleaning
How to Clean Composite Decking
Quick answer
Identify the composite decking before choosing a cleaner or pressure washer. For ordinary dirt, many current boards can be cleaned with the maker’s approved soap-and-water method and a soft brush. Product generations differ: Trex permits specified pressure cleaning on certain newer lines while advising against it on early-generation decking. Never transfer one line’s limits to another.
Before you start
The boards, fascia, railing, fasteners and lighting may have different care requirements. This guide uses hand cleaning on a sound deck; it excludes construction residue, coating removal, damaged boards and structural repairs. If the brand or product generation cannot be confirmed, ask the installer or manufacturer before a whole-deck wash.
Supplies
- The exact decking care guide, a soft nonmetal brush and clean water.
- One approved cleaner, soft cloths and suitable collection tools for ordinary leaves and loose debris.
- Label-required protective equipment, barriers and a plan to keep runoff away from storm drains and adjoining property.
Step-by-step method
- 1. Inspect the dry deck and photograph persistent marks. Check for damaged caps, lifted boards, loose railings or areas that feel unstable. Keep people away from defects and have them repaired before washing. Confirm that recent installation or repairs have been released for normal care.
- 2. Lift movable furniture and pots without dragging their feet. Gather ordinary leaves and litter, including accessible material near board gaps, without gouging the boards or probing concealed fixings. Stop if the debris includes cement powder, paint fragments or an unknown construction residue.
- 3. Test the approved cleaner and soft brush on a discreet board. Include an embossed section if the surface has a wood-grain texture. After the manufacturer’s required rinse, let the test dry and check color, gloss and the cap’s appearance.
- 4. Clean a few boards at a time, following the product’s directions. Use gentle brushing to work dirt out of the surface texture rather than scrubbing one dark spot aggressively. Keep rinse cloths and the brush clean so that removed grit is not dragged back over the cap.
- 5. Remove the dirty liquid and rinse thoroughly as specified. Trex notes that dirty water left to dry can leave a film. Keep the rinse moving toward planned collection rather than beneath doors or into drains. Do not let cleaner dry while you work far ahead.
- 6. Inspect the dry result. Separate remaining marks into likely ordinary soil, mineral spots, leaf-related discoloration or physical scuffs. Ask the manufacturer for the matching treatment instead of applying a wood-deck stripper or generic solvent.
- 7. Return furniture only after the deck and item feet are dry. Check whether protective mats or planter supports are permitted for the decking; some materials can leave discoloration. Save the approved product and method in the property’s maintenance notes.
Check the result and avoid common mistakes
- Do not sand composite boards to remove a mark. Trex warns that sanding changes the surface and can affect warranty coverage.
- If pressure washing is permitted for the exact line, follow its nozzle, pressure and minimum-distance instructions plus the machine manual. Hand cleaning remains an option.
- Avoid chemical mixtures and do not assume railing instructions also apply to boards or vice versa.
Keep it easier next time
Clear leaves and ordinary debris before they sit damp on the deck, and pay attention to shaded spots and the areas under planters. Maintain access to board gaps without scraping them. A small inspection after wet weather helps you notice drainage issues before the next full cleaning session.
When to stop
Stop for cap damage, loose components, construction powder, unknown products or a failed patch test. Do not use a pressure washer from a ladder or against an unapproved surface. Significant staining or deterioration needs the decking supplier’s assessment rather than escalating force.
A practical next step
For business and office cleaning or post-construction cleaning in Orange County, Chino or Ontario, California, contact JLV Cleaning and Maintenance to discuss your space at /contact/.