How to Stain a Concrete Patio

1. Step 1: Choose the Right Stain for the Look You Want

Concrete patio stain comes in three families, and they produce very different results from the same method. Acid stain is a solution of metallic salts in mild acid that reacts with the lime in the concrete, so the colour forms inside the slab and comes out variegated and translucent. Water-based penetrating stain carries fine pigment into the pores without a chemical reaction, so the colour you choose is close to the colour you get. Solid-colour stain is essentially a thin opaque coating that hides the concrete completely.

For a plain, even colour, which is what this guide covers, acid stain is usually the wrong tool. Direct Colors, which makes acid stain, says plainly that you should not try to make it uniform because the variation is the look. That mottling is exactly what makes acid stain good for imitating natural stone, and if that is the result you want, our guide to staining a concrete patio to look like stone covers the layering technique. Come back to the sealing steps here when you are done.

Semi-transparent water-based stains sit in the middle. Behr's Premium Semi-Transparent Concrete Stain, one of the most widely sold options, is a siliconized 100 percent acrylic with about 17 percent solids by volume according to its technical data sheet, so it behaves like a very thin, tinted coating that lets some of the concrete's texture show through. Behr's own data sheet points buyers who want a uniform solid colour to its solid-colour product instead. That is a useful rule across brands: semi-transparent for a tinted concrete look, solid for a uniform painted look.

If you are torn between stain and paint, the deciding question is whether you want to see the concrete. Stain lets texture and some variation show and cannot peel if it is a true penetrating product; paint and solid stains hide flaws but can peel if prep or moisture is wrong. Our comparison of concrete stain vs paint covers that choice in detail, and our best outdoor concrete stain guide ranks specific products in each family.

2. Step 2: Check the Slab Before You Buy Anything

Start with age. New concrete has to cure before it will take stain properly, and the labels are consistent on this: Behr asks for a minimum of 30 days for its semi-transparent stain, and Direct Colors says a new slab must cure 30 days before acid staining and should look a uniform light grey. Staining too early gives uneven colour because the slab is still giving off moisture at different rates across its surface.

Next, find out whether anything is already on the surface. Sprinkle water in several places. Direct Colors' guidance is that if it soaks in within a minute or two, the concrete is likely porous enough to stain; if it beads or sits, either a sealer or coating is present, or the slab is bare but too dense. A rainbow sheen in the beaded water points to a coating that has to be stripped, while no sheen on a slab you know is bare points to a smooth trowelled finish that needs etching or light grinding to open it up.

Check for moisture coming up from below by taping a square of clear plastic to the slab for about 24 hours. Condensation under the plastic or darker concrete beneath it means moisture is moving through, which can upset both the stain and the sealer. On an outdoor patio that usually means waiting for a drier spell or improving drainage rather than abandoning the project, but it is worth knowing before you commit to a film-forming sealer.

Finally, look honestly at the surface. Stain is translucent, so it shows what is underneath: patches, oil ghosts, rust marks, efflorescence and areas of different concrete will all read through a semi-transparent colour. If the patio has several repairs or a mismatched extension, a solid-colour stain may be the realistic choice. If it is sound and reasonably consistent, a semi-transparent or water-based penetrating stain will look far better than paint.

3. Step 3: Clean, Strip and Etch the Patio

Preparation decides the result more than the stain does. Begin with spot treatment: work a degreaser into oil and grease marks one at a time and rinse them, so you are not spreading thin oil across the whole patio when you wash. Remove paint spots, adhesive, caulk and any rust with the appropriate cleaner. Direct Colors lists paint, glue, oil, grease, curing compounds and old sealer among the contaminants that cause light spots and blotchy colour, and the same applies to water-based stains.

If the water test showed a sealer, strip it completely and evenly. Patchy removal produces patchy colour, because stain only goes where the old film has gone. Behr's instructions call for removing old coatings or sealer with a stripper before cleaning and etching, and a solvent-based acrylic can often be softened with xylene and scrubbed off. Penetrating sealers cannot be stripped and must wear away, so a patio sealed with a silane or siloxane in the last few years may not be stainable yet.

Then wash the whole surface. A pressure washer with a fan tip held at a sensible distance cleans without cutting into the surface, which matters because wand marks from a turbo nozzle show through translucent stain. Our guide to pressure washing a patio covers technique. For semi-transparent acrylic stains, follow with an etch: Behr's data sheet calls for cleaning and etching with a muriatic acid etcher or its own cleaner-etcher to achieve a profile similar to 150-grit sandpaper.

After etching, rinse thoroughly and check for residue. Behr's instruction is to wipe your fingers over the clean, dry surface and make sure no dust or powder comes off; if it does, rinse again. Then do the water test once more. If water is quickly absorbed and the surface feels like 150-grit sandpaper, it is ready. If not, etch again. Let the patio dry completely before staining, at least 24 hours in good weather and longer when it is cool, humid or shaded.

4. Step 4: Test Absorption and Colour on a Hidden Patch

Every slab takes stain differently, and the only reliable preview is a test on your own concrete. Pick a corner that is out of the main sightline but has the same finish and exposure as the rest, such as behind a planter or along the house wall. Apply the stain exactly as you intend to on the whole patio: same dilution, same number of coats, same tool. Then seal the test area with the sealer you plan to use, because sealer usually deepens and changes the colour substantially.

Direct Colors explains why this step matters more than it used to: many modern concrete mixes replace part of the cement with other materials, which can reduce how strongly a slab reacts with acid stain, and homeowners rarely know what mix was used. A weak or uneven test result on acid stain is a signal to switch to a water-based product rather than to try harder. Water-based and semi-transparent stains are more predictable, but absorption still varies with the finish, which is why the test matters for them too.

Look at the finished test in daylight, in shade and when wet. A colour that looks right on a small swatch can feel too dark across a whole patio, and dark colours absorb heat; Behr recommends light and pastel colours on pool decks for exactly that reason. If you want a lighter result with a semi-transparent stain, check the label before diluting, because some products, Behr's included, say not to thin. Choosing a lighter colour is the safer route.

Write down what you did so you can repeat it exactly. Note the colour, any dilution, the number of coats, the tool and roughly how much product the test area took. Use that to estimate quantity: Behr's data sheet gives 250 to 500 square feet per gallon for its semi-transparent stain depending on application method and porosity, but a rough broom finish will drink more than a smooth one, and buying all the cans at once lets you intermix them for an even colour.

5. Step 5: Apply the Stain in Small, Even Sections

Pick your weather window first. Behr specifies air and surface temperatures between 50 and 90°F, no direct sunlight, a dry surface, and no rain or heavy dew expected within 24 hours. In practice that means starting on a mild, overcast day or working into the shade as the sun moves. A slab that is hot to the touch makes stain dry too fast and leaves lap marks. Mask the house wall, door thresholds, plants and anything else you do not want coloured, and move furniture well clear.

For semi-transparent acrylic stain, Behr's method is to work in small sections of about 4 by 4 feet, applying with a quality pump sprayer at a fine setting in a circular motion, working quickly and feathering the edges. If you want a more uniform look, back-roll immediately with a short-nap roller. Stir the stain before and during application and intermix cans so the colour stays consistent. Let the first coat dry, which Behr puts at about 1 hour to touch and 4 hours before recoating, and add a second coat for a darker, more even finish.

Plan your route so you never have to walk on wet stain, and use the patio's control joints as natural stopping points. A straight stop line in the middle of a panel will show; a stop at a joint will not. Keep a wet edge within each section, and if you must stop, feather the edge rather than leaving a hard line. Keep a damp rag handy for drips on the house wall or steps, and wipe them immediately.

If you are using acid stain after all, the routine changes. Use an all-plastic pump sprayer, because acid reacts with metal, wear goggles and acid-resistant gloves, and spray in random overlapping motions. Direct Colors says to leave its acid stain for a minimum of 4 to 8 hours depending on colour, up to about 12 hours for the deepest result, and never beyond roughly 24 hours, after which the colour can overdevelop into a flat tone. In hot, dry weather it suggests lightly dampening the slab so the stain does not dry too quickly.

6. Step 6: Neutralise and Rinse Acid Stain

This step applies only to acid stain. Water-based and semi-transparent stains do not need neutralising; you simply let them dry for the time on the label before sealing. Acid stain, on the other hand, leaves the surface acidic and coated in a chalky residue of spent stain and minerals, and both have to go before any sealer touches it. Direct Colors calls leftover residue the most common cause of peeling sealer on acid-stained concrete.

Direct Colors' method is to saturate the surface with a neutraliser, scrub it in gently with a soft nylon brush, let it sit about 20 minutes, then scrub again. Its FAQ says baking soda at 1 to 2 tablespoons per gallon of water, or ammonia, will also neutralise, but they can leave their own residue and need extra rinsing. Wear the same protective gear you used for staining, because the slab is still acidic until this step is done.

Then rinse, and keep rinsing. Pull the rinse water up with a wet/dry vacuum rather than pushing it around with a mop or hosing it into the lawn. Direct Colors' test is that the rinse water should come up clear, not cloudy or tan, and that once the slab is dry, a hand or white rag wiped across it should pick up no colour and no chalk. If either test fails, rinse and vacuum again; it is much cheaper than stripping and resealing a peeling patio.

Let the patio dry completely before sealing, which Direct Colors puts at several hours to overnight depending on temperature, humidity and airflow. Outdoors, give it at least a full dry day. Sealing over a damp slab or leftover residue is what causes hazing and adhesion failure, and both are far harder to fix after the sealer has cured than before it goes on.

7. Step 7: Seal the Stained Patio and Let It Cure

Sealing protects the colour from foot traffic, weather and UV, and it is what makes the stain look finished. For most stained patios the sealer is a clear acrylic in either a high-gloss wet look or a low-lustre finish. Behr suggests its Wet-Look Sealer for high gloss or its Low-Lustre Sealer for a low-gloss finish over its semi-transparent stain, and its 2020 data sheet says to allow the stain at least 24 hours to dry before topcoating. Apply two thin coats rather than one heavy one, at the temperatures on the sealer's label.

Mind the slip and heat warnings. Behr's label cautions that stained surfaces may become slippery when wet, and that its wet-look and low-lustre sealers should not be used around pool decks or other areas subject to constant moisture. Any glossy film adds slip risk on a patio, so on steps, slopes and around water, add a non-slip grit to the sealer or choose a lower-sheen product. Our acrylic vs penetrating sealer comparison explains the trade-off between a film and a breathable sealer.

Give the finish time before you use it. Behr's guidance for its semi-transparent stain is light foot traffic after 24 hours, 72 hours before heavy foot traffic or repositioning furniture, and parking tyres on corrugated cardboard for 7 days where vehicles are involved. It also says to wait 30 days before cleaning, then use a mild, non-abrasive detergent. Your sealer may carry its own, longer cure times, and the longer of the two is the one to follow.

After that, maintenance is mostly about the sealer. A true penetrating stain does not wear off on its own, but the sealer over it does, and a worn sealer lets the colour abrade in traffic paths. Do a water-drop test once a year and recoat with a compatible sealer when the main walkways stop beading. Our guide to how long concrete sealer lasts covers realistic intervals, and if you are still weighing whether a stained patio needs sealing at all, our guide on whether to seal concrete walks through the decision.

If the plain colour turns out well and you want to go further, the natural next step is variegation: accent colours, faux joints and layered acid stain that make a slab read as flagstone or slate. That is a different technique with different colour rules, and our guide to staining a concrete patio to look like stone picks up where this one leaves off.