There are numerous choices when it comes to outdoor patio surfaces, including decomposed granite, concrete, pavers, flagstone, slate and tile. Each has its own advantages and disadvantages in terms of cost and design, so it’s important to determine your exact patio needs before making a decision. A relatively new choice has been gaining popularity in recent years: acid etch stained concrete. “Acid etch stained concrete is one of the most cost-effective, highly stylized patio surfaces available,” says Alan Kostelnik, owner of Gardens of the Wine Country. “It’s so attractive that it’s become common to see it used for interior flooring and countertops.”
Acid etched stain applications work best on newly poured or installed concrete, but the process can also be applied successfully to old concrete. The key to refurbishing old concrete is an extremely clean surface, free of all stains, oils, grease and sealers. The acid etch chemicals must be able to react with the chemicals in the concrete, so it’s important to remove any foreign materials that might contaminate the process. If you can’t get the surface sufficiently clean, you can pour a thin concrete veneer over it. It also may be necessary to sand or pellet blast the surface.
After you’ve thoroughly cleaned your old concrete surface, consider the following tips for applying acid etched staining:
• Make sure you move, cover and tape off any surrounding vegetation to limit overspray damage from the acid etch coloring agent.
• Wear protective clothing, including safety glasses and rubber gloves and boots. Mix the acid etch coloring agent in a plastic bucket.
• It’s best to apply the etching agent with a garden sprayer. Keep the spray wand about 18 to 24 inches from the surface and keep it moving. You want the surface thoroughly wetted but not puddling.
• Let the surface dry for about an hour. If you want it darker, spray again after the first drying period.
• After the floor has dried completely, neutralize the surface by spraying it with a solution of one part ammonia to four parts fresh water.
• Once you’re completely done, you can spray the entire surface with a sealer to give it vibrancy and depth.
