The Best Deck Cleaners of 2026: Compared & Ranked

For most wood decks the best deck cleaner is an oxygen bleach cleaner — sodium percarbonate, sold as a powder you mix with warm water — followed by an oxalic acid wood brightener. The oxygen cleaner lifts dirt, mildew and the grey, sun-damaged fibres off the surface; the brightener neutralises the cleaner, removes tannin and iron stains, and returns the wood to something close to its natural colour. That two-step pair is what most stain manufacturers ask for on their labels, and it is the right preparation for any new finish.

Chlorine bleach is the cleaner most people reach for and the one to avoid on wood: it kills mildew but leaves the dirt and grey fibres behind, attacks the wood's lignin and corrodes fasteners. If the deck still carries old stain you want gone, a cleaner will not shift it — that is the job of a caustic stripper. And composite decking is its own case, with its own rules set by the board manufacturer.

Deck Cleaner Types and What Each Removes

Deck products are sold under overlapping names — "deck wash", "wood cleaner", "restorer", "brightener", "deck revive" — and the name rarely tells you the chemistry. The active ingredient does. There are five families worth knowing.

Oxygen Bleach (Sodium Percarbonate)

Sodium percarbonate is sodium carbonate — washing soda — bonded to hydrogen peroxide. Dissolved in water it releases both: the peroxide oxidises organic staining and mildew, and the mildly alkaline carbonate loosens dirt and the soft, UV-degraded cellulose that makes old wood look grey. It does this without the fibre damage of chlorine, and it breaks down to water, oxygen and soda ash, which is why it is the gentlest effective option around plants. Its limitation is shelf life once mixed: the solution is most active in its first few hours, so it should be made fresh, ideally in warm water, and used the same day.

Sodium Hypochlorite (Chlorine)

Household bleach and many "outdoor cleaners" are sodium hypochlorite. It decolourises mildew and algae almost instantly, which makes a deck look cleaner faster than anything else. On bare wood that speed is deceptive, for reasons covered below. On composite, vinyl, concrete and other hard surfaces it is a legitimate tool.

Caustic Strippers

Strippers are strongly alkaline, usually sodium hydroxide based, and they work by saponifying oil binders and softening acrylic films so they can be scrubbed and rinsed away. They will also remove heavy grime, but they darken wood noticeably — cedar and redwood can turn almost brown — and raise the grain. Every stripper job needs a brightener afterwards.

Oxalic Acid Brighteners

Oxalic acid does three things. It neutralises the high pH left by cleaners and strippers, which matters because many stains penetrate and cure poorly on alkaline wood. It dissolves iron-tannate stains — the blue-black marks around steel fasteners and under metal furniture. And it reverses much of the darkening that alkaline products cause, so the wood ends up lighter and more even. A brightener alone does not clean; it finishes the job a cleaner starts.

Composite Deck Cleaners

Products sold for composite are typically mild detergents, sometimes with an oxygen booster, formulated to lift dirt and surface mildew from plastic-capped boards without scratching or dulling the cap. They are milder than wood cleaners because the job is milder: there is no grey fibre layer to remove.

Cleaner vs Brightener vs Stripper

The easiest way to pick is to diagnose the deck before buying anything. Look at the boards and decide which of four conditions you have.

Dirty, green-tinged or with black mildew spots, but still the colour of wood: a cleaner. If you are not about to stain, a cleaner and a rinse is the whole job.

Silver-grey and fuzzy: a cleaner and then a brightener. The grey is a thin layer of UV-degraded fibres, often only a fraction of a millimetre deep. An oxygen cleaner with a stiff brush removes it; the brightener evens out the colour. This is the standard sequence before staining weathered wood.

Dark streaks, black rings around nail heads, or reddish-brown runs on cedar or redwood: a brightener. Those are tannin and iron stains, and no cleaner will shift them, while oxalic acid usually clears them in minutes.

Old stain still on the boards — peeling film, patchy semi-transparent colour, or a solid stain you want to change: a stripper and then a brightener. Before committing to that, check whether you need to strip at all. A penetrating semi-transparent stain that has simply faded can often be cleaned and recoated with the same product. A peeling film cannot — new stain over a failing film fails with it. Our guide to how to strip deck stain covers the full stripping process.

The Best Deck Cleaners

These are widely sold products described by their published characteristics, ranked for the most common job — preparing a weathered wood deck for stain — with picks for maintenance, stripping and composite. The ranking favours chemistry that is effective without damaging wood fibre, clear labelling, and how well each product fits into a cleaner-then-brightener sequence.

Home-centre brands such as Olympic and Behr also sell deck cleaners and all-in-one wood cleaners, and they can do a perfectly good job. Read the active ingredient rather than the name: oxygen-based and detergent-based cleaners suit stain prep; anything listing sodium hypochlorite should be treated like the chlorine products above.

The Picks at a Glance

Why Chlorine Bleach Is a Poor Wood Cleaner

Chlorine bleach makes a mildewed deck look clean in minutes, so it is easy to see why people use it. The problems show up later.

It does not clean. Hypochlorite decolourises organic staining; it does not dissolve dirt, and it does not lift the grey layer of degraded fibres. The deck looks lighter, but the surface stain has to bond to is unchanged. Stain applied over it penetrates poorly and fails early.

It damages the wood. Chlorine attacks lignin, the natural binder that holds wood fibres together — the same substance UV light breaks down when wood turns grey. Repeated bleaching leaves a fuzzy, washed-out, unnaturally pale surface that absorbs stain unevenly and often has to be sanded to recover.

It leaves residue and corrodes metal. Salt residue left in the wood can interfere with finishes if it is not rinsed out exhaustively, and chlorine is corrosive to fasteners, joist hangers and hardware. On pressure-treated lumber, whose copper-based preservatives already make fastener choice important, that is not a risk worth adding.

It is harsh on plants. Runoff damages grass and shrubs, and mixing bleach with ammonia-containing or acidic cleaners releases toxic gas — one reason never to combine products in a sprayer.

Oxygen bleach does the job chlorine is being asked to do — kill and remove mildew — while also removing dirt and grey fibres, and without the damage. That is why stain manufacturers almost universally specify it, and why we only recommend chlorine for non-wood surfaces or as a targeted spot treatment.

Cleaning Before You Stain

Most stain failures trace back to preparation rather than the product in the can. Stain has to soak into sound, clean, dry wood fibre; anything sitting on the surface — dirt, mildew, grey fibres, mill glaze or old finish — becomes the weak layer the new stain peels or flakes off with. Whichever product you are planning to use from our deck stain comparison, the preparation sequence is the same.

1. Repair first. Reset proud nails, replace rotten boards and sand splinters before you clean, so the cleaner reaches everything in one pass.
2. Strip if needed. If the water-drop test shows old finish, or you are changing product, strip it now and rinse.
3. Clean. Oxygen cleaner, dwell, scrub, rinse.
4. Brighten. Apply the brightener while the wood is still damp, dwell, rinse thoroughly.
5. Dry. Wait at least 48 hours of dry weather — longer in cool or humid conditions. If you have a moisture meter, most stain makers want readings in the low teens or below.
6. Sand lightly if fuzzy. Cleaning and stripping raise the grain. A quick pass with 60–80 grit on a pole sander knocks down raised fibres; going finer than 100 grit closes the surface and reduces absorption.
7. Stain. Check the forecast and temperature — our guide to how to stain a deck walks through application, and the deck stain drying time guide covers how long before rain and foot traffic.

New Wood

New lumber is not clean just because it is new. Smooth-planed boards can carry a compacted surface layer that resists absorption, and pressure-treated lumber is often too wet to stain for weeks or months after installation. Most stain makers recommend cleaning or a dedicated new-wood prep, then a brightener, once the wood has dried enough to accept water readily. The water-drop test applies here too: if water beads, the wood is not ready.

Cedar and Redwood

Tannin-rich woods benefit more from brightening than any other species. Cleaners and especially strippers darken them, and their natural tannins react with iron to leave black stains. A brightener is close to mandatory under a transparent or semi-transparent finish. Our guide to cedar deck stains covers why cedar behaves differently and which finishes suit it after prep.

Application, Plant Protection and Rinsing

Conditions

Work in the shade or on an overcast day, with air and surface temperatures in the cleaner's labelled range — typically above 50°F and below about 90°F. Cleaners that dry on the wood stop working and can leave residue and lap marks; direct sun on a dark deck in summer will dry a solution in minutes. Morning or late afternoon is usually best.

Protecting Plants and Surroundings

• Soak plants, lawn and soil around and below the deck with plain water before you start. Saturated leaves and soil absorb far less of the cleaner that drips onto them.
• Cover delicate plants with breathable cloth or plastic sheeting during application, and remove plastic as soon as you finish — plastic in sun cooks what is under it.
• Rinse plants again after each section and at the end of the job.
• Protect hard surfaces. Wet down siding, masonry and glass nearby and rinse any overspray promptly. Brighteners in particular can etch or mark stone, and caustic products can dull glass and aluminium.
• Wear protection. Goggles, chemical-resistant gloves and long sleeves for every product here; acids and caustics both injure eyes quickly.

Applying the Cleaner

Wet the deck lightly first — damp wood spreads cleaner more evenly — then apply with a pump-up garden sprayer, working in sections of perhaps 100 square feet, from the house outwards. Let it dwell for the time on the label, typically 10–15 minutes, and mist with more solution or water if any area starts to dry. Scrub with a stiff synthetic-bristle brush on a pole, along the grain. Never use a steel brush or steel wool on wood: fragments rust and leave black tannin stains, which is exactly what you are trying to remove.

Rinsing — Low Pressure

A garden hose with a good nozzle is enough after a thorough scrub. A pressure washer saves time but is the commonest way decks are damaged during cleaning. Softwood fibres between the growth rings erode much faster than the hard latewood, so excessive pressure carves furrows and leaves a raised, fuzzy surface that looks worse after staining than it did before.

• Pressure: roughly 500–800 psi for cedar, redwood and other soft woods; pressure-treated pine tolerates somewhat more, but there is rarely a reason to exceed about 1,200 psi.
• Tip: a 25- or 40-degree fan tip — never the zero-degree tip.
• Distance and direction: hold the tip 12 inches or more from the surface, keep it moving, and work along the length of the boards, overlapping passes.
• Surface cleaners: a rotary pressure washer surface cleaner gives a very even rinse on flat boards without wand stripes, provided the washer's pressure is turned down to suit wood. Keep it moving and test on a hidden area first.

Let the chemistry and the brush do the cleaning; the water is only there to carry away what they loosened. If you find yourself turning up the pressure to remove grey wood, the cleaner needed longer dwell time or more scrubbing.

Cleaning Composite Decking

Composite decking does not turn grey in the way wood does, will not accept stain, and should never be stripped, so most of the wood-prep sequence does not apply. What it does get is dirt, pollen, food and grease spills, and — especially on older, uncapped boards, where wood fibre is exposed at the surface — mould and mildew.

Follow the board manufacturer's care guide. It is the only authority that counts for warranty purposes, and guides vary. In general, composite makers recommend warm soapy water or a composite deck cleaner and a soft-bristle brush for routine cleaning; many allow a sodium hypochlorite-based cleaner for mould and an oxalic-acid brightener for tannin or rust spots; and most restrict pressure washing to a fan tip at a set distance and a maximum pressure — exceeding it can scar the cap layer and void the warranty.

• Routine cleaning: twice a year with a mild cleaner, a soft brush and a hose rinse. Clean the gaps between boards so debris does not hold moisture against them.
• Mould and mildew: a chlorine product such as 30 SECONDS where the care guide allows it, or Wet & Forget for gradual no-rinse treatment.
• Grease and oil: wipe spills quickly and use a degreaser approved by the board maker; set grease is far harder to remove.
• Rust and tannin marks: an oxalic acid brightener, spot-applied and rinsed.
• Avoid: caustic strippers, acetone and strong solvents, steel brushes and steel wool, and any abrasive that dulls the cap.

Concrete, pavers and the patio slab at the foot of the steps need different products again — oxygen and alkaline masonry cleaners that would be too harsh for wood. Our driveway cleaner guide covers those.

Common Mistakes

Using chlorine bleach as the stain prep. The deck looks clean, the stain goes on, and within a season it is flaking off a layer of grey fibres the bleach never removed.

Skipping the brightener. Oxygen cleaners and strippers leave wood alkaline and darker than it should be. Stain over that surface looks muddy, and on some products penetrates and cures less reliably.

Too much pressure. A zero-degree tip or a tip held a few inches from the wood gouges furrows that no stain hides. If the wood looks fuzzy after rinsing, sand it before staining.

Letting cleaner dry on the boards. It stops working, leaves residue and creates blotches. Smaller sections, shade and misting prevent it.

Staining too soon. Wood that feels dry on the surface can still be wet inside after cleaning. Two dry days is the minimum, and more is better in cool, humid weather. Temperature matters too: our guide to what temperature to stain a deck covers the window.

Mixing products. Never combine chlorine with ammonia or acid products, and never mix a cleaner and a brightener in one sprayer — they neutralise each other at best and produce harmful fumes at worst. Rinse the sprayer between products.

The Short Version

For a weathered wood deck about to be stained, buy an oxygen bleach cleaner and an oxalic acid brightener — Restore-A-Deck Wood Cleaner followed by Defy Wood Brightener is a sound pairing, as is either brand's own matched kit. If old stain needs to come off, swap the cleaner for a caustic stripper and keep the brightener.

For a finished deck that just turns green each spring, Wet & Forget is the lowest-effort fix. For composite, follow the board maker's guide and keep a fast chlorine cleaner such as 30 SECONDS for stubborn mould where it is allowed.

Whatever you use: protect plants, keep the cleaner wet while it dwells, scrub along the grain, rinse at low pressure with a fan tip, and give the wood at least 48 dry hours before any stain goes on.

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