How to treat outdoor teak furniture, step by step

Outdoors, teak takes a beating: sun, rain, leaves and birds. Yet it is one of the few woods whose makers say you hardly need to do anything to it. This page goes deeper into the practical side of outdoor care: which product to choose, exactly how to apply it, when, and what to do in winter.

Not sure whether to treat your teak at all, or want to see the indoor/outdoor and colour/grey decision tree first? Start with how to treat teak: the complete guide.

Outdoors: three routes

Outdoors, you are really choosing between three options. Tribù and Gloster describe them almost identically:

1. Do nothing except clean. The teak turns silver-grey. Tribù calls this cosmetic, with no effect on quality or strength (Tribù). Gloster recommends this route itself (Gloster). More on the grey look in letting teak go grey.
2. Let it go grey, but make it stain-resistant with a colourless protector. Tribù recommends this “if you prefer the silver-grey patina” (Tribù instructions).
3. Keep it brown for longer with a sealer containing UV-blocking agents, which according to Tribù slows down the greying “considerably”, but does not stop it (Tribù instructions).

A fourth option, teak oil, we deliberately leave out: Tribù, Gloster and Vincent Sheppard advise against oil on outdoor teak. It adds no protection, and according to Gloster and Tribù it can lead to mould and black wood (Gloster, Tribù, Vincent Sheppard). The full story is in teak oil or sealer.

Note: brands differ on combining protector and sealer. Tribù says its protector and sealer cannot be used on the same surface; to switch, you first sand the surface and let the teak adapt for one or two weeks (Tribù instructions). Gloster, by contrast, advises a protector on top of its sealer (Gloster). Advice: choose one system from one manufacturer and stick to it.

Before you start: the conditions

A treatment fails more often because of the timing than because of the product. The manufacturers name these conditions:

• Cool wood, in the shade or on a cloudy day. Tribù advises cleaning in cloudy weather or in the shade, with furniture that has cooled down completely (Tribù instructions).
• Clean and completely dry before you apply a protective product; Gloster says “100% dry and free of dust” (Gloster).
• A dry spell afterwards. Tribù: after applying, protect the furniture from rain for 24 hours to avoid water stains, and never put covers on recently treated furniture (Tribù instructions). Gloster has its protector dry for 48 hours after the second coat before use (Gloster).
• Protect the ground and yourself. Gloster advises eye protection, rubber gloves and covering the ground (Gloster); Tribù warns about sensitive flooring (Tribù instructions).

Step 1: cleaning

Regularly, during the season

Tribù describes a light weekly clean during the outdoor season: first sweep off loose debris with a soft hand brush, then clean with mild, pH-neutral soapy water and a microfibre cloth or sponge, always along the grain (Tribù instructions). Gloster keeps it to a thorough clean once or twice a year with water and a mild detergent (Gloster). How often you do it mostly depends on how clean you want it.

Deep clean, once or twice a year

Following Tribù’s instructions (source):

1. Brush loose dirt off with a hand brush, along the grain.
2. Mist the surface with tap water, for example with a plant sprayer.
3. Pour some teak cleaner onto a microfibre cloth and dab it over the whole surface.
4. Leave it to work for two to four minutes; if it starts to dry, mist on a little more water.
5. Brush firmly along the grain with a soft brush or brush pad.
6. Leave it for another minute, keeping the surface moist.
7. Rinse thoroughly with clean water and let the furniture dry in the open air.

Gloster describes a similar method, with soaking time, a scrubbing pad and a thorough rinse (Gloster).

Don’t use: abrasive sponges, steel brushes, “wonder” (melamine) sponges or abrasive or caustic cleaners, and no pressure washer or steam cleaner (Tribù instructions). Gloster adds steel wool and bleach to that list; steel can leave rust spots and bleach discolours the wood (Gloster).

Step 2: sanding (only when needed)

Sanding outdoor teak is not a yearly chore. The manufacturers name two situations:

• Light sanding if the wood feels rough after cleaning or the grain has risen (Gloster).
• Repair if dirt or mould has got deep into the wood or the surface is damaged. Tribù then advises sanding down to the unaffected layer, along the grain, starting coarse with P80 and working gradually finer to P150–P220. Leave the wood untreated for one or two weeks afterwards before protecting it again (Tribù instructions).

Never sand across the grain (Gloster), and wear a dust mask: the Dutch timber information centre Centrum Hout notes that substances in teak can cause skin complaints in sensitive people (Centrum Hout, Dutch). If a piece really needs a major overhaul, read more in teak garden furniture care.

Step 3: protecting

New teak

Tribù advises leaving new teak untreated outdoors for about two to three weeks before applying protector or sealer (Tribù instructions). Gloster has you clean new teak first, so the natural teak oil is off the surface before you protect it (Gloster). New teak also releases oil and pigment in its first months; Gloster gives two to three months and advises against standing new teak on pale, porous stone paving (Gloster).

Applying protector (Tribù method)

1. Furniture clean, dust-free and dry.
2. Shake the bottle vigorously and pour a little product onto a clean, dry microfibre cloth.
3. Wipe it on along the grain; don’t use too much, or it turns sticky.
4. Let it absorb, then apply a second coat after four hours.

Tribù recommends this at least twice a year (Tribù instructions). Gloster uses a spray: soak the surface, dry for four hours, apply a second coat, then let it dry completely for 48 hours; once a year, twice on table tops (Gloster).

Applying sealer (Tribù method)

1. Open the tin and stir with a clean stick.
2. Wipe on a thin coat with a clean, dry microfibre cloth, along the grain; use a medium to fine brush for awkward corners.
3. The sealer is absorbed within the hour; then apply a second thin coat.
4. Wipe off any excess, or the surface stays sticky.

Tribù recommends this once a year and gives a handy test: as long as water beads on the surface, the sealer is still active (Tribù instructions). Gloster has you test on a hidden spot first to check you like the colour (Gloster).

When to treat outdoor teak

What	Gloster	Tribù
Thorough clean	1–2× a year	light weekly clean in season, deep clean as needed
Protector	1× a year, table tops 2× (April and October)	at least 2× a year
Sealer	at least 1× a year	1× a year

Sources: Gloster, Tribù instructions.

Gloster explicitly links the second table-top treatment in October to winter: those horizontal surfaces are the most exposed (Gloster). A dry week in spring and one in autumn are therefore logical moments. For tables specifically, see teak table care.

Everyday use: small things, big effect

Tribù’s instructions give a few practical tips that are often overlooked (source):

• Move pots, vases and plastic coasters regularly, or they can leave dark marks.
• Avoid plastic tablecloths on teak.
• Remove spilt food and drink, fallen leaves, berries, blossom and bird droppings as quickly as possible to avoid stains and mould.

Vincent Sheppard adds that black stains and mildew are often caused by rainwater or sap from trees, and advises against placing furniture under trees (Vincent Sheppard). And pale cushions? Teak releases oil that can stain them; Tribù calls this a naturally repeating process (Tribù).

Winter: leave it out, store it or cover it?

Leaving it out is fine. Tribù says untreated teak can stay outside all year round, even in extreme weather (Tribù). The Dutch teak company Teak.nl says the same, but advises putting furniture under a roof if you can, especially pieces with moving parts such as steamer chairs and folding chairs (Teak.nl, Dutch). Worth knowing: according to Tribù, teak used indoors or on a veranda does not turn grey (Tribù instructions).

Storing it? Clean and protect the furniture thoroughly first, and store it only in a dry, unheated and well-ventilated room (Tribù instructions). Gloster suggests a dry garden shed or garage and warns explicitly: don’t move teak straight from the garden into a heated room, as the sharp difference in temperature and humidity can make the wood move too much and split (Gloster). If you want to move an indoor piece outside instead, read using indoor teak outdoors.

Covering it? This is where advice diverges:

• Teak.nl advises against protective covers for teak, because covered teak is much more prone to mould (Teak.nl, Dutch).
• Gloster recommends its own breathable covers to keep off dirt from leaves, birds and splashes, on condition that the furniture is completely dry, the cover is removed regularly and standing water on the fabric is removed (Gloster, covers).
• Tribù: never non-breathable plastic covers (Tribù instructions).

Conclusion: teak does not need a cover. If you use one anyway, choose a breathable one, only cover dry wood, and make sure there is ventilation.

Normal, not damage

• Fine cracks in the end grain from changing temperature and humidity do not affect durability or strength, according to Vincent Sheppard (Vincent Sheppard).
• Irregular discolouration from natural oil coming to the surface can be removed with the deep clean above, according to Tribù (Tribù instructions).
• Wasps stripping weathered teak in spring and early summer to build their nests (Gloster).