How to Prepare a Painted Concrete Patio for Stain

Stained concrete is becoming increasingly popular, showing up regularly inside homes and restaurants. A variety of designs and faux painting techniques can make concrete mimic wood, leather or natural stone. Stained concrete on the patio instantly improves the appearance of your outdoor space.
Unlike paint, which covers flaws, stain will magnify any imperfections on the concrete's surface. If your concrete patio currently has a layer of paint, thoroughly remove it before applying stain.

Things You'll Need

• Hose or pressure washer
• Non-flammable chemical stripper
• Putty knife
• Hydrated lime
• Denatured alcohol
• Stiff bristle brush
• Wet vac

Instructions

1. Thoroughly hose down your patio with a pressure washer or garden hose. Use a high pressure attachment on your hose to create the most force. Allow the patio to dry completely.

2. Apply non-flammable chemical stripper to the painted patio surface. Chemical strippers are available at your local home improvement store. Try to find a product that is environmentally friendly to minimize damage to nearby grass and plants. Allow chemical stripper to penetrate the paint surface according to the manufacturer's instructions, usually 20 to 30 minutes.

3. Scrape paint with a putty knife or floor stripper. Repeat using the chemical stripper and scraping until the majority of paint is removed.

4. Mix hydrated lime and denatured alcohol to form a thin paste. Rub the mixture onto remaining paint spots. Let the paste dry, forming a bond with the paint, then remove it from the patio floor with a stiff-bristled brush.

5. Clean chemical residue off the patio using water and a wet vac. Avoid letting the water run off the patio into areas with grass and plants.

6. Remove any remaining paint using a concrete grinder. Grinders are available for rent at a local equipment rental retailer. This step is optional and should be considered a last resort. Grinding will etch the surface of the concrete and change the effect of the staining process.

References

• Cleaning Floors