How to clean a yacht teak deck without damaging it

How often should a teak deck be cleaned?

Light routine cleaning often, a deep scrub when the teak turns grey or green, and sanding only during a refit.

Routine cleaning is a gentle wash with fresh water and a soft pad to lift salt, footprints and everyday dirt before it works into the grain. Doing it often keeps each clean light, and light cleaning is what keeps the wood on the deck.

A deep scrub is for when the teak has gone grey, or green in shaded areas where algae takes hold. It needs a slightly more aggressive pad and more time per section, but it is still a cleaning job, not a sanding job.

Sanding removes wood, so it belongs in a refit, when there is time to check the caulking and finish the deck properly.

What damages teak?

Pressure washers, hard brushes used along the grain, strong two-part acid cleaners used too often, and scrubbing a dry deck. Each one removes soft wood and exposes the caulking.

• Pressure washers cut into the soft grain and can lift the caulking at the seams.
• Hard brushes worked along the grain dig out the soft wood between the rings.
• Two-part acid cleaners brighten teak quickly, but used too often they eat the surface and shorten the life of the deck.
• Scrubbing a dry deck turns the pad into an abrasive. Without water to carry the dirt away, it sands instead of cleaning.

Teak has hard growth rings with softer wood between them. Aggressive cleaning takes the soft wood first, leaving a ridged surface that holds dirt, feels rough underfoot and lets the caulking stand proud of the planks.

Which machine should I use?

The JÖST Teak Scrubber, Cleaner & Sander for large open decks, and the Deckie for side decks, stairs and tight areas.

The JÖST Teak Scrubber, Cleaner & Sander is an oscillating machine with a 190×340 mm pad. It covers aft decks, sun decks and foredecks quickly and evenly, and with the right pad it also sands. €150/day, VAT incl.

The Deckie is the compact machine, with a 120×250 mm pad. Use it for side decks, stairs, the swim platform and the corners the JÖST can’t reach. €100/day, VAT incl. Many crews rent both: the JÖST for the open areas, the Deckie for the detail.

Why oscillating? The pad moves in short, fast strokes and stays flat on the deck, so it cleans evenly across its whole surface. Unlike orbital or rotary machines, it doesn’t throw water and dirt across the deck and up the superstructure, and it doesn’t pull or dig in at the edges, so it stays easy to control on a wet deck.

Which pad for which teak?

GREEN for weathered teak that still has enough wood, RED for routine cleaning of teak in good condition, and Grey Microfiber with water only for new or delicate teak.

• GREEN (medium): weathered, grey or green teak with plenty of wood left above the caulking.
• RED (slight): routine cleaning of teak in good condition.
• Grey Microfiber, water only: new or delicate teak.
• Very thin, old teak: always Microfiber, never GREEN.

JÖST pads are €14.89 for GREEN or RED and €34.99 for Microfiber. Deckie pads are €5.49 for GREEN or RED and €19.89 for Microfiber. For a yacht of around 50 m, plan on about four GREEN pads for the JÖST. All pads are in the JÖST pad collection.

If you’re unsure, start with the gentler pad and only step up if it isn’t lifting the dirt.

How do I clean a teak deck step by step?

Clear the deck, wet it and keep it wet, work in shaded sections, let the machine do the work, rinse often, squeegee, and let it dry.

1. Clear the deck of furniture, cushions, mats and anything loose.
2. Wet the whole area well with fresh water, and keep it wet for the entire job.
3. Work in sections, out of direct sun. Plan around the sun so no section dries before it is rinsed.
4. Guide the machine in steady, overlapping passes and let it do the work. Don’t add pressure: the machine’s weight and the pad are enough.
5. Rinse often, so loosened dirt is flushed away instead of being worked back into the grain.
6. Squeegee the water off towards the scuppers.
7. Let the deck dry completely before anyone walks on it or the furniture goes back.

When should teak be sanded instead?

When the deck is uneven, the caulking stands proud, or there are deep stains cleaning won’t lift. Do it during a refit.

Sanding takes a layer of wood off, so do it once and do it properly, when there is time to check and repair the caulking afterwards. The JÖST sands as well as cleans, so the same machine can handle both jobs on a refit.

For interior wooden floors, the Lägler Trio gives fast, even sanding right up to the edges, at €300/day, VAT incl.

What are the most common mistakes?

Most deck damage comes from going too hard: the wrong pad, a deck that dries mid-job, full sun, or chemicals the deck doesn’t need.

• Too aggressive a pad on thin teak. Once the wood is gone, it’s gone, so thin teak gets Microfiber and water only.
• Letting the deck dry mid-job. A dry pad abrades, and dirty water dries into the grain and leaves marks.
• Cleaning in full sun. Water evaporates before you can rinse, leaving streaks and uneven colour.
• Using chemicals the deck doesn’t need. Most routine cleaning needs only water and the right pad.

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