Concrete stain is a fast, simple way to turn your dull gray patio into a lively, colorful surface that will make your outdoor space more inviting. The stain is nearly foolproof to apply—just wet the concrete and spray on the stain. If you’re not happy with the result, you can go back and apply a second or third coat to enhance the color.
In this story, we’ll show you how to apply the stain, including ideas for mixing stains to create a unique, multicolored surface that looks like marble. You’ll save a substantial amount of money by doing it yourself, and you won’t need any special tools—just basic painting tools and rain-free weather. If you’re cutting kerfs into the concrete, you’ll need a diamond masonry blade for your circular saw.
You can apply the stain over worn concrete, but don’t expect a miracle. You’ll still be able to see the old appearance through the stain. And avoid staining spalling concrete. The stain will turn a darker color wherever the concrete is pitted.
What is concrete stain?
Concrete stain is a water-based product that coats the concrete and becomes a permanent part of the surface. The stains can fade and wear over time, but sealer helps protect them.
Concrete stains are different from acid (or etching) stains, which chemically react with minerals in the concrete to change the color. Acid stains are available for DIYers, but there are fewer colors to choose from, and applying it involves more steps.
Time, money and materials
You can do this project in a weekend. Prep the concrete and apply the stain on Saturday, then seal it on Sunday. If you decide to add a second coat of stain, you’ll need another day.
The stains are available at home centers in the paint section—the color is added just as with paint. One gallon covers 200 to 400 sq. ft. A gallon of sealer also covers 200 to 400 sq. ft.
The color you choose may look slightly different after it’s applied. Each patio will accept the stain a little bit differently. However, the color will be close to what you see in the brochure.
The stain is semitransparent. It won’t completely cover the surface as paint would. You’ll see the concrete through the stain, especially if you’re using a light color.
Cut kerfs and clean the concrete
This project is much faster and easier if you stain your whole patio a single color. All you have to do is wet the concrete and apply the stain. Then backroll with a 3/8-in.-nap roller if you want even coverage. That’s it—there’s no need to block off sections or switch sprayers. If you want a pattern with different colors, start by deciding on a color scheme. Anywhere you want to switch from one color to another, such as for a border or the checkerboard pattern shown here, you’ll need a kerf (a shallow cut in the concrete). This gives the colors a crisp separation. Taping off the concrete won’t work. The stain will run under the tape.
If you already have expansion joints in the concrete, incorporate them into your design to avoid cutting kerfs. But if you need to cut kerfs, start by snapping a chalk line where you want to cut. It’s important for the cuts to be perfectly straight. Crooked cuts will be obvious once you apply the stain. So use a wide board as a saw guide and weight it down with buckets of water (Photo 1).
Install a diamond masonry blade in a circular saw and set it to a depth of 1/4 in. The cuts don't need to be deep—just enough to separate colors. Have a helper spray a water mist on the blade during the cut to contain the dust (Photo 1). Don't use cheap abrasive blades for cutting concrete—you can't spray them with water, and you'll end up with dust all over your siding and windows.
You won't be able to get the saw blade right next to the house, so finish off the kerfs with a masonry chisel and a hammer or a grinder with a diamond blade.
As with any other staining project, surface preparation is critical. Any stains, such as rust, will show through in the finished project. Clean the entire surface with a heavy-duty cleaner (Photo 2), working in 4 x 4-ft. sections at a time. Then rinse the concrete with water until you don’t see any more soapy bubbles. For tough rust stains, use a stain remover, and rinse it off with water. For grease or oil stains, use a product that's designed to remove those stains. Blast dirt and debris out of the kerfs with water.
Prep the area for staining
Now that the concrete is clean, make sure your shoes are, too, before you walk on the patio again. The surrounding ground will be wet from concrete cleaning. We changed into a pair of clean, dry shoes to work on the patio. Before cracking open the stain, shield the lower portion of the house and any nearby landscaping materials to protect against drifting spray. Tape plastic film along the siding. You don't have to protect plants and grass if you don't want to (any stain that gets on them will hardly be noticeable). If any dirt gets on the patio after you've cleaned it, brush the concrete lightly with a broom to avoid pushing the dirt into the surface.
Apply the stain
You shouldn't apply the stain in direct sunlight (partial or full shade is best), so wait for a cloudy day or a time of day when the patio is shaded. Also avoid windy days so the stain won't drift. You'll need a few garden sprayers for this project—one for each stain color you’re applying and one for water. Fill the sprayers over tarps on the grass (don't fill them on the patio since spills will stain the concrete). Test the spray pattern on cardboard.
If you're creating a pattern, you'll need shields to place in the kerfs or expansion joints to prevent spraying onto adjoining areas. We used fluorescent light lenses (available at home centers), but you could use cardboard. Have four or five on hand. Don't use them if they're dripping wet with stain or they’ll drip onto (and stain) the concrete.
Work in small sections (4 x 6 ft. or so), starting near the house and working outward. Plan the application so you don't box yourself into a corner.
Start by spraying the concrete section with water. Get it wet but don't leave standing water. To create the marbleized look shown here, have a helper hold the shields in the kerfs (if necessary) and apply the first color (base coat) of stain in a circular pattern (Photo 3). The base coat makes the second color more prominent. Immediately after spraying, mist the section with water and apply the second color (Photo 4). Then spray more water over the top to create swirls or small runs in the second color (Photo 5). The first and second colors will intermix, producing the marbleized effect. Use the water to “push” the color all the way to the edges or onto bare spots. If the water pools in a low spot or starts to run onto an adjacent section, dab it up with a cloth.
When switching to a new stain color, be sure the lens shields are dry, or use new shields so the old color doesn't run onto the section of the patio with the new color. Don't worry if a leaf or debris blows onto the wet stain. After the stain dries, remove the debris and touch up the stain (see the next step).
Add more stain for deeper color
Let the stain dry for 24 hours. If the color isn’t as vibrant as you want or the coverage is spotty, go back and add another coat of stain. Wet the concrete and apply the stain using the same steps as before. We added a second coat to the corner squares of our patio to give them a deeper, richer color.
You’ll probably find bare spots that you missed, especially along the edges. Touch-up is simple. Fill a spray bottle with stain, spray the stain on a cloth and dab it on the bare spot (Photo 7).
Finish with the sealer
The manufacturer says the sealing step is optional, but we recommend it because it protects against fading and wear, and it enhances the stain. You’ll have to clean the patio with heavy-duty cleaner and give the patio a fresh coat of sealer every three to four years.
Give the stain a full day to dry, then apply the high-gloss sealer. Choose a day or time of day when the patio is shaded (don’t apply the sealer in direct sunlight). Start by cutting in with sealer along the patio edges with a 3-in. brush. The milky white sealer turns clear as it’s applied. Roll sealer on the rest of the patio with a 3/8-in.-nap roller (Photo 8). Let the sealer dry for two hours, then apply a second coat. Roll the second coat perpendicular to the first coat.
This project can be as basic or as elaborate as you make it. Keep it quick and simple by applying a single color to your entire patio. Or divide your patio into sections as we did and color them differently. Apply layers of different colors for a "marbleized" look or spray two colors at the same time for a one-of-a-kind look. If you don’t like the result, just keep applying new colors until you get the look you want. To see hundreds of examples of how stain can enrich concrete, do an online search for "stained concrete," then click on the "Images" option.