Acid Staining Concrete Floor

If you want to attempt acid staining, concrete floor appearance will change from what now looks like a plain, dull job to an incredible, leather-look flooring with caramel accents. Whether your concrete floor was newly laid or if you’ve wondered for years how to possibly make it presentable, acid staining is your perfect solution.

Caution: Acid Staining Mixtures Contain Corrosive Acid Liquids.

They may cause skin, eye or respiratory irritation. Store safely and keep them away from children. Do not allow any runoff during application, rinsing and clean up into your sewage system. Do not consume them internally, obviously, and avoid contact with eyes, skin or clothes. Always wear protective clothing, goggles and rubber gloves when handling and using, and use with adequate ventilation.

Acid Staining: Preparatory Steps

1) First, you should cover all the wall bases with a sheet of 12-inch masking paper – this will protect them from discoloration, should any acid spray on the walls. If you have exposed cabinets or metal screws in sight, cover these as well.

2) When you mix your acid stain, do it outside or in a location that has excellent ventilation. In fact, when you begin your job, it may be a good idea to open all the windows and perhaps rent a fan to make sure there is proper airflow through the house.

3) You’ll need to wear heavy-duty protective gloves and goggles, since hydrochloric acid is the main component of your staining mixture. The acid stain should be placed in a two-gallon pump machine with entirely plastic materials – remember, hydrochloric acid is highly corrosive when it comes in contact with metal.

4) If the cement was hand trowelled, the stain should be diluted with water, using four parts water to one part of stain. If the cement floor was machine trowelled, you should have a more concentrated mixture of one part to one part. The more water you add, the color will also change and can thus be controlled in this manner.

5) Use the stain outside on a test area before you get started inside. This is also a good way to get the sprayer started, and make sure that it creates an even, smooth stain flow. When you’ve done this, you can begin on your inside floor.

6) As you apply the acid stain, maintain your sprayer wand at least 18 inches above the floor’s surface. Apply the stain in a random fashion, making sure the floor is thoroughly covered – as you work, be sure to avoid creating puddles. You’ll notice that where the cement contains more lime, you’ll have a darker stain hue.

7) Allow the first coat of stain to fully dry, which should take about an hour. A second coat can then be applied, and you may repeat the process until you’ve reached the color you were hoping for.

8) After this is complete and the floor is dry, you can begin cleaning up. Again, if you’re working with a hand trowelled cement floor, you’ll need to spray the floor with a mixture of one part ammonia and four parts water, in order to neutralize the hydrochloric acid. You can use a two-gallon plastic pump sprayer to apply this mixture as well.

9) Once the floor has dried completely, clean the floor with a new mop. If there is extra water on the floor, use a shop vac to pick it up, and let the floor dry again.

10) You can seal the floor with a high-gloss water-based sealer, though you may also consider waxing the floor or trying out a sealer that is solvent-based. Depending on the product you choose, you’ll find that the application instructions vary, so be sure to read all the instructions before moving ahead with the sealing process. You don’t want to skip this step however, as it is what will protect your newly-stained concrete from everyday wear – and it will also help to fully bring out the new color of the acid stain.

See Also: Patching a Basement Floor