Wood is easier to damage than concrete, so deck cleaning requires lower pressure and more attention to the finish. Start with sweeping, a compatible cleaner, and gentle brushing.
Identify the wood and finish
Pressure-treated wood, cedar, composites, and painted or stained surfaces have different limits. Follow finish instructions before using chemicals.
Test cleaner in an inconspicuous spot
Look for discoloration, raised grain, or finish damage. Do not mix cleaners and protect nearby plants.
Brush with the grain
A suitable brush and proper dwell time often reduce the need for high pressure. Work in sections so cleaner does not dry on the surface.
Too much pressure can scar the deck
If using a pressure washer, use a wide fan, adequate distance, and the lowest effective pressure. Let the deck dry thoroughly before applying stain or sealer. After cleaning, let the wood dry adequately before deciding whether it needs stain or sealer. Trapping moisture beneath a finish can cause poor adhesion and shorten the life of the coating.
Sources
- American Cleaning Institute — Cleaning Tips — Household cleaning practices, product dosing, and label-compatible surface care.