How to Stain Concrete Floors and Patios

Both concrete stain and concrete paint can be used to refresh concrete. However, stain is often the best choice because it actually soaks into the concrete. This is different than paint, which provides a tough upper coat that wears off faster. Keep in mind that with stain, the outcome is permanent. You must work carefully for successful results. The amount of stain depends mostly on the size of the area to be covered. Overall, plan on the project taking several days due to drying time.

Knowing how to stain a concrete floor begins by choosing a concrete stain that fits your needs. There are two types of concrete stain to choose from, water-based and acid-based. Your choice will depend on such factors as the desired look, location and budget.

• Water-based stains work by bonding to concrete surfaces. The stain fills the pores and produces a colored film or coating. Water-based stain is typically less expensive than acid-based products. This stain is typically used for DIY design projects, particularly indoors. As water-based stains usually require sealer for protection, they work well in lower-traffic areas. Available in multiple colors, it's easy to apply and ensures consistent results. This stain gives off lower volatile organic compounds (VOCs). It's safe, eco-friendly, non-toxic, dry quickly and have little odor.
• Acid-based stain reacts with concrete to create a permanent chemical bond. It is ideal for high-traffic or exterior areas, like garages. As it won't peel or chip, it helps produce a natural-looking, durable finish. This promotes permanent, mottled, earth-toned results. Acid-based stain is also resistant to both fading and ultraviolet (UV) light. But it does emit hazardous fumes. As such, intensive preparation and cleaning is required to neutralize acid residue. This makes this stain more expensive and time-consuming to use.

In some cases, homeowners who want to know how to color concrete use concrete paint, rather than permanent stain. For garages, driveways and porches, choose high-performance options that will withstand hot tires, automotive oil and UV rays. Finally, test the stain on a small piece of concrete to check on the color and coverage.

The most important step of how to stain a concrete floor is surface preparation. New concrete should be at least four weeks old.

Begin by removing all items from the floor and cleaning the area thoroughly. Sweep and mop to remove all dust, dirt and debris. They will show through the stain and can impact the finished look. If needed, use a pressure washer to clear stubborn marks and discoloration from the old concrete.

This is also a good time to repair cracks in the concrete surface. All repairs should be completed before starting the stain application. Coatings of any kind must be removed before staining. Use a concrete crack sealant according to product instructions to fill any gaps along the floor. Allow at least 24 hours for the product to fully dry. Then, use a floor scrubber to buff away any uneven patches.

• Do not use muriatic acid to clean. It will destroy the important minerals necessary to produce the color range selected.
• Strip and remove all previous sealers, paints, adhesives and coatings. For oil spots, use a degreaser and neutralizer (diluted 4 to 1). Be sure to rinse the area well.
• For acid staining, use a concrete etch and cleaner to prepare the surface. Again, rinse well.
• Concrete must be porous enough to accept water. Dense concrete surfaces may require mechanical preparation to accept acid stain. The stain can bead up on top of the concrete. But you'll need to sand the concrete to ensure the stain will soak in properly.
• Mask for over-spray with masking tape and water-resistant construction paper. Apply duct tape over masking tape to prevent stain bleeding.

Use an acid-resistant airless paint sprayer to neatly and evenly apply the stain on the concrete slab. You may also use a paint roller or handheld brush for stain application in smaller areas and tight corners on the slab. Work in sections, as needed. Go over each sprayer coat with the paint roller for a smooth and uniform finish.

• Dampen the area with water. But do not let it puddle.
• Spray in an overlapping manner, maintaining a wet edge.
• Allow acid stain to react with the concrete floor for at least 6 hours.
• Clean residue and pour water on the floor to approximate the final color. If a darker color is desired, apply a second coat.
• Clean residue from floor with degreaser and neutralizer solution using an acid brush. Repeat.
• Rinse with clean water and mop up excess water. Use a wet-dry vacuum, if needed. Rinse with clean water until the rinse water is free of color. You should also be able to wipe the floor without picking up color.
• Concrete must be completely free of residue. Expect to rinse it with clean water several times.
• Once dry, test the readiness of the concrete by wiping the floor with a white cloth. If it shows residue, rinse and dry again. Repeat until no residue remains.

Water-based stains do not generate excess residue. Review the label instructions and follow the manufacturer's guidelines for the correct drying time.

Safety Tip: Wear safety gear when staining cement and concrete. Protect your skin, face and lungs from chemicals. And make sure the area is well-ventilated.

Concrete sealers protect the finish of your stained concrete. Test before application. Use clear sealer to enhance the depth of color and to repel dirt, water and environmental wear. Choose a concrete sealer that offers the right amount of gloss and durability for your needs.

Allow the stain to cure for a full 24 hours. Then, spread the sealer along the floor, as directed on the label. Drying time for the sealer can vary depending on environmental conditions. Plan on two days for it to completely harden. You may want to consider using a concrete floor polish to help reduce slipping and scuffing.

Keep these tips in mind as you are learning how to stain concrete.

• Test a small section. Allow it to completely dry before staining the entire area. Preview the finished look and decide if the color is a good fit before applying the full first coat.
• Use painter’s tape along the bottom of each bordering wall to avoid stain splatters in unwanted areas.
• Allow new concrete to cure for at least a month before applying stain.
• Use a plastic airless sprayer for acid staining. Metal parts are prone to damage and corrosion.
• For water-based stains, spray the area in circular motions. Doing so avoids pooling on concrete flooring.
• Remove any existing concrete sealer before applying a new stain color.