How to Acid Wash Concrete

Acid washing is also known as acid etching. It involves using muriatic acid to remove stains from concrete, preparing the surface for staining or creating designs for aesthetics. This is not to be confused with acid staining, which can be done after preparing the concrete floor by muriatic acid washing.


  1. Image titled Acid Wash Concrete Step 1
    Hose down the entire area. If the acid could come into contact with any of the surrounding surfaces, wet those down, too. This includes walls, cabinetry, carpeting, doors and door frames. Remove any furniture in close proximity.
  2. Image titled Acid Wash Concrete Step 2
    Mix the acid in a plastic bucket. Fill the bucket with water first, then sprinkle the acid into the container slowly. Use 3 or 4 parts water to 1 part acid. The proper concentration will depend on how shiny the flooring is: If the concrete is shiny, very hard or smooth, you'll want the mixture to be stronger.
  3. Image titled Acid Wash Concrete Step 3
    Pour the acid wash solution into a spray bottle or plastic not metal sprinkling can. Spray or sprinkle the solution onto the concrete flooring you're etching. Immediately start scrubbing the floor, or get the floor machine going. If you're using a machine, you'll need to manually do the corners and other areas the machine can't access. Keep the floor wet throughout the process; you may need to hose it down every few minutes.
  4. Image titled Acid Wash Concrete Step 4
    Neutralize the acid after you're done scrubbing. Mix the neutralizing solution in a new spray bottle according to the manufacturer's instructions, then spray it onto the floor. Scrub or use the machine again to ensure that all the acid is neutralized. Pay particular attention to the edges and any low spots in the concrete.
  5. Image titled Acid Wash Concrete Step 5
    Rinse the floor again. Use a push broom to gather the water into one area. Suck up the used water with a shop vacuum. Call your local hazardous materials disposal center and ask how to properly dispose of the waste water according to your local regulations.


  • Use a helper if you can. The process will move faster if you can scrub the floors while someone else keeps the hose going.
  • A 5 gallon (18.9 L) bucket of acid solution will cover approximately 150 square feet of concrete flooring.


  • Never add the water to the acid. Always add the acid to the water to prevent dangerous acid splashes, then mix the solution slowly.
  • Keep the entire area wet throughout the process. This helps keep the acid from permanently damaging the materials. Muriatic acid will not only eat away at the concrete, it will damage metal, wood and synthetic materials like carpet.
  • Muriatic acid is undiluted hydrochloric acid; it is extremely dangerous. Wear gloves, protective clothing and goggles to avoid getting it on your skin or clothing.

Things You'll Need

  • Hose
  • Muriatic acid powder
  • 5 gallon (18.9 L) plastic bucket
  • Water
  • Stirrer
  • 2 spray bottles or sprinkling cans
  • A wire scrub brush or floor scrubbing machine
  • Neutralizing solution
  • Push broom
  • Shop vacuum

Article Info

Categories: Concrete