How do I clean teak outdoor furniture without damaging it?
Short answer
Clean teak with a mild solution of a teak-safe cleaner or a little dish soap in warm water, a soft brush and a hose rinse, working with the grain. For gray, mildewed or heavily soiled teak, a two-part teak cleaner or an oxygen bleach followed by a brightener restores the honey color. Avoid pressure washers, steel wool and chlorine bleach. Rinse thoroughly and let the furniture dry completely in the shade before oiling or sealing, if you choose to.
What teak is and why it cleans so well
Teak is dense, oily and full of natural silica, which is why it was used for ship decks and why it lasts outdoors with no finish at all. Dirt, pollen, sunscreen and mildew sit on the surface of teak rather than soaking in, so cleaning is mostly a matter of lifting that layer without scrubbing away the wood under it.
Teak near the coast does pick up a couple of specific problems: black mildew spots from the damp marine layer, and a gray weathered surface from UV. Both clean off. Neither is damage to the wood itself.
Routine cleaning
For furniture that is just dusty or has a season of use on it, keep it simple.
- Mix a mild cleaner in warm water. A squirt of dish soap works. So does a commercial teak cleaner that is labeled as mild or one-step.
- Wet the piece down with a hose first so the cleaner does not soak into dry wood unevenly.
- Scrub gently with a soft-bristle brush, always with the grain. Pay attention to the joints and the undersides of arms and seats where mildew starts.
- Rinse well. Soap residue left on teak attracts dirt and feeds mildew.
- Dry in the shade. Drying fast in direct sun can raise the grain and open fine checks.
Restoring gray or mildewed teak
Teak that has gone gray and spotted needs more than soap. Two approaches work.
A two-part teak cleaner uses an acidic first step to lift the gray and a neutralizing second step to bring back the color. These are effective and quick, but the first step is aggressive and needs careful rinsing. Overuse of two-part cleaners year after year does slowly erode the surface, so we reserve them for furniture that really needs it.
The gentler path is the same chemistry we use on decks: a sodium percarbonate oxygen bleach to lift the gray and kill mildew, a thorough rinse, then an oxalic acid brightener to neutralize and restore the honey tone. It takes a little longer and is easier on the wood.
Either way, the furniture comes out looking close to new teak. At that point it needs to dry for several days before anything goes on it.
What not to do
Most teak damage we see is from cleaning, not from weather.
- No pressure washers. Teak is hard but the grain still tears, and a washer leaves a fuzzy surface that grays faster and catches dirt.
- No steel wool or wire brushes. They leave steel particles that rust into black spots.
- No chlorine bleach. It breaks down the surface fibers, washes out the color and leaves a chalky look.
- No scrubbing across the grain. Scratches across teak grain show for years.
- No oiling dirty or damp teak. Oil over mildew feeds it; oil over wet wood will not cure.
After cleaning: finish or not
Clean teak can be left bare to weather back to silver, or it can be sealed to hold the honey color. That is a real choice with trade-offs, and we cover it in its own answer. The short version is that bare teak needs only a cleaning every year or so, and sealed teak needs a cleaning and a recoat on a similar schedule to keep the color even. Traditional teak oil is the option we steer people away from, for reasons that also get their own answer.
Related questions
How often should I clean outdoor teak?
A gentle wash once or twice a year is enough for most pieces, usually in spring after the rains. Furniture in shade or near sprinklers may need a mildew check more often. A deep clean and brighten is only needed when the piece has gone gray and you want the color back.
Can I sand teak instead of cleaning it?
A light sanding with fine paper after cleaning smooths raised grain and small checks. Sanding instead of cleaning removes wood every time, and on thin slats that adds up. Clean first, sand lightly only if the surface needs it.
Will cleaning remove the black spots?
Mildew spots come off with an oxygen bleach cleaner or a two-part teak cleaner. Black spots that remain after cleaning are often iron stains from a nearby fastener or from steel wool, and an oxalic acid brightener lifts those.