How to Acid Stain Concrete Floors – A DIY Guide

Concrete floors are durable, hard working, and can be quite comfortable in warm climates. Unfortunately, they can also be unbearably ugly. If you're tired of looking at dull, grey concrete and want to learn how to stain concrete floors, here is a basic concrete staining technique.

Prepare the Surface
Concrete that will be stained needs to be cleaned, completely dry, and free of any chips, scratches, and stains. If your current floor isn't perfect, consider applying a coat of fresh concrete and allowing it to cure before attempting to stain your floor. Fill in all cracks, chips, and gouges, and allow to dry. Sand the surface smooth with a drum sander, then vacuum up all the dust. Remember, every flaw in your floor's surface will show through the stain, so the more you do to improve the floor, the better the finished result will be.

While you prepare the area, take a moment to protect the other surfaces of the room. Tape up plastic sheeting along baseboards, walls, and cabinets. Do not get tape adhesive on the concrete itself.

After sanding and cleaning up the dust, the floors should be cleaned with a degreaser, such as tri-sodium phosphate or plain dish detergent. Rinse the floor, and allow it to dry for at least twenty-four hours before proceeding.

Etching
Etching concrete is usually done with a spray on acid mixture. Etching powders are also available, but many people find the spray easier to use. Wear goggles, a face mask, sturdy boots and gloves, and avoid spraying walls as much as possible.

Mix the acid according to the manufacturer's instructions, and pour into the sprayer. Spray a fine mist of acid on the floor, starting in the corner farthest from the door and working your way backwards out of the room. The acid will bubble like peroxide when it touches the concrete. Do not attempt to soak the floor with your concrete acid stain. You should try to apply the acid as evenly as possible, in a very thin coat.

Allow the acid to dry for another twenty four hours, then test the color. To test, put a small amount of water on the floor and see what the color is. If you like the result, neutralize and seal the floor.

If you want a darker color, apply another coat of acid on top of the first coat. Wear rubber soled shoes when walking across acid to avoid leaving footprints. Allow the second coat to dry for twenty four hours, and test the color again.

Neutralize and Seal
To neutralize the acid, mix half a pound of baking soda with five gallons of water, and use this mixture to wet mop the floor. Allow the baking soda mixture to sit on the floor for at least thirty minutes. Using a new mop and clean water, rinse the baking soda solution by mopping the floor two or three times. Finally, pour clean water across the floor, and use a shop vac to remove the water and baking soda residue. Allow to dry another twenty four hours.

Seal your newly stained floor with either an acrylic or polyurethane concrete sealant. Make sure the floor is completely dry before sealing, and use a soft bristle brush to apply the sealant. Work slowly, and avoid getting air bubbles in the sealer by applying it in thin, even coats. Follow the manufacturer's recommendations in regards to room temperature and drying time.

Tagged as: concrete, floors, how to, stain