Can You Use Vinegar to Clean Your Deck? Here's What Experts Say – and What to Use Instead

Somewhere in the pantry there's probably a gallon of white vinegar that already cleans the coffee pot and the shower door. Vinegar costs next to nothing and smells like salad dressing instead of bleach; many people use vinegar to clean a deck for exactly those reasons, without a second thought about where the rinse water goes.

Out in the yard, white vinegar already has a few honest jobs. Some gardeners use vinegar in the garden to scrub crusty clay pots and burn back weeds in sidewalk cracks. That same weed-killing action is part of the problem on a deck, though. Acetic acid burns plant tissue on contact, and a bucket of rinse water doesn't stop at the edge of the boards.

It also matters what the deck is made of. A cedar deck that has never seen a drop of stain, for example? Well, that doesn't play by the same rules as Trex, a major composite brand that actually approves vinegar for one particular job. Check the maker's care guide before any cleaner goes on.

Can I Use Vinegar to Clean a Deck?

On some composite boards, the answer is a qualified yes. If your boards are one of Trex's current lines, white vinegar is on the approved list for hard water deposits: the chalky white spots a sprinkler leaves when it keeps hitting the same boards.

Rinse well afterward; everyday dirt gets warm soapy water and a soft-bristle brush instead, scrubbed down into the embossed grain. Be aware that Trex says anything containing acid or bleach can lighten the color of its boards, so try a small spot near the steps first.

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Other brands say less. TimberTech's care guide doesn't mention vinegar at all, and it points owners toward its own diluted deck cleaner or, for railings, a pH-neutral detergent. It also warns against citrus cleaners, solvents and several brand-name deck cleaners on its current capped boards. When a manufacturer hasn't approved a product, using it anyway means guessing how the surface will react.

Wood decks raise a different question, and the finish on top matters more than the boards underneath. Acids aren't foreign to deck care – oxalic acid brighteners are a standard step for pulling gray discoloration out of bare wood before a fresh coat of stain.

That's prep work for unfinished boards, though; once paint or stain goes on, the can it came in has the final word. Some finish makers approve only their own cleaners, and washing a stained deck with straight vinegar again and again means working outside those directions with no way of knowing how that particular finish will hold up.

Then there's everything growing below the deck rail. Household vinegar is about 5% acetic acid, the same acid sold in stronger form as a weed killer, and it damages leaf tissue wherever it lands.

Picture that rinse water running off the edge of the deck onto a bed of hostas or a row of fall lettuce – leaves that it soaks can turn brown and crispy, and seedlings take the worst of it. The acid doesn't hang around in the soil, and lawn grass along the edge usually recovers better than broadleaf plants do. A natural label? It sadly doesn't change any of that.

Safer Alternatives to Clean a Deck

The broom comes out first, since scrubbing wet leaves only smears them across the boards. Home Depot's 7-pattern Ames hose nozzle set has a soft shower setting for soaking the deck and a narrow jet for packed gaps. Warm water and a squirt of dish soap handle ordinary grime on wood and composite alike.

Brushes are where the two big composite brands part ways. Trex wants soft bristles, and Home Depot also carries a soft-bristle Unger scrub brush that threads onto a standard broom handle. TimberTech calls for medium-to-stiff nylon on its composite instead. Do one section at a time and rinse it before the suds dry.

Mildew and gray weathering on a wood deck usually need something stronger than soap. Walmart carries DEFY's powdered wood cleaner, an oxygen-based formula for exterior wood that mixes up in a bucket.

Now, at least one stain maker warns that chlorine bleach can damage both the finish and the bare wood fibers, and it's hard on any plants it splashes. Capped composite needs more caution here (TimberTech's guide says its own diluted cleaner is the safe bet). Think about where the bucket water goes, too, especially if the deck slopes toward a fish pond or a storm drain. A label that says biodegradable means the product breaks down eventually, not that it's harmless to fish and other pond life along the way.

Pressure washers are tempting on a big deck, but a narrow stream held too close can tear up the surface of wood boards and leave the fibers fuzzy. Composite brands set firm limits. On Trex Transcend, Enhance and Select boards, the limit is 3,100 psi with a fan tip held at least 8 inches (20.3cm) from the surface, though the company doesn't recommend pressure washers at all on its early-generation lines. TimberTech caps pressure at 1,500 psi, for rinsing only, with the spray running along the grain.

Decks that get washed twice a year are far less likely to need anything harsh. Trex ties its spring and fall schedule to pollen and leaf litter, since that buildup is what mold grows on. Leaves wedged between boards can hold water against the surface long after a rain, and a putty knife slid down the row clears them out quickly. Shady corners and boards under overhanging branches usually go green first.

Keep the vinegar, just not as the everyday deck cleaner. On Trex boards with chalky sprinkler spots, it's the fix the company itself approves, and the potting bench can use it too. Day-to-day grime comes off with warm soapy water and a brush that won't scuff the boards, ideally on a gray afternoon when the sun isn't drying the suds faster than you can scrub.