How should I clean and maintain a teak deck on my boat?
The teak deck on my yacht has gone grey, with green patches around the fittings and some darker areas in the cockpit. How should I clean it without wearing the wood away, and should I oil it afterwards?
Answer
Clean your teak deck with mild soapy water and a sponge or very soft brush, working across the grain, then rinse thoroughly with fresh water. Leave clean, untreated teak to turn silver-grey naturally, and use specialist cleaners or algae treatments only where ordinary washing fails.
Inspect the wood and seams
Inspect the deck while it is dry, before scrubbing. Look for open caulking seams, loose black sealant, missing screw plugs and raised plank edges. Cleaning cannot repair these faults, and gaps can let water beneath the teak.
Check whether you have solid teak, a thin teak overlay or synthetic decking. An older screwed deck may have substantial planks but little wood left above the fasteners. A modern bonded overlay may have only a thin wearing surface. Neither should be sanded just because it looks dirty.
Run your fingertips across the planks. Deep grooves between raised grain show previous wear, often caused by hard brushing. Remove the dirt while preserving the remaining timber; do not chase an even, freshly sanded colour.
Wash gently across the grain
Choose a cool, overcast day so the deck stays wet while you work. Gather a bucket, mild detergent, a sponge or very soft brush, and a hose with a gentle flow.
- Lift loose mats and move ropes aside. Gently sweep away sand and grit, or lift it with a damp cloth.
- Wet a manageable section of deck. Wash with warm water and a little mild soap, following the detergent manufacturer's dilution instructions.
- Work across the grain with light pressure. Scrubbing along the grain removes softer timber between the harder grain lines, leaving ridges.
- Rinse thoroughly with fresh water before the soap dries, including around fittings, seams and drains.
- Let the deck dry before judging the result. Wet teak looks much darker.
Clean seawater is useful for routine washing when cruising, but avoid dirty harbour water. Water and a sponge are often enough for ordinary upkeep. Add soap when there is dirt or grease to remove.
Do not use a pressure washer, stiff deck brush or abrasive scouring pad. They can strip wood quickly, particularly around seams and weathered grain.
Treat algae and stubborn stains
Green patches usually develop where moisture lingers: beneath ropes, beside fittings and under poorly ventilated covers. Clean these areas first, then improve drainage and airflow so they dry between wettings.