Muriatic acid (also called hydrochloric acid) is one of the most dangerous chemicals available for amateur use in the home. It is not a primary solution cleaning product, but rather a last-resort for removing stubborn stains on badly discolored concrete. When acid washing your garage, be sure to exactly follow the product instructions based on the specific brand and strength of muriatic acid you purchase.
Things You'll Need
- Muriatic acid
- Protective clothing & equipment
- 5-gallon bucket
- Mop or sprayer
- Baking soda or garden lime
Acid Washing a Garage
Purchase muriatic acid from your local home improvement store, and read the label. While most muriatic acid is sold in a standardized concentration of 34 percent acid, it is possible to find different concentrations in some locations. Always follow the package instructions in regard to acid/water ratios.
Wear protective clothing. Rubber or vinyl-coated gloves are a must, as are acid-rated safety glasses and a respirator. For additional safety, consider vinyl-coated coveralls and a full-face respirator or safety mask.
Prepare your muriatic acid and water mixture in a 5-gallon plastic bucket. Always add acid to water, and not the other way around. Mixing water into acid can cause dangerous chemical reactions and acid splatter.
Apply the acid wash to the garage floor using a mop or sprayer, working quickly and evenly. Note that whatever you use to apply the mixture may be damaged by the acid, so if you opt for a sprayer, use a disposable plastic one.
Let the acid sit on the floor for the prescribed length of time, and no more. Muriatic acid can permanently damage your floors if left on too long.
Rinse the acid mixture away using a hose or (preferably) a pressure washer. Contain as much of the runoff as possible, as muriatic acid can damage sewage lines and harm wildlife.
Neutralize the garage floor by sprinkling liberally with baking soda or garden lime. Allow to rest until all fizzing has ceased.
Remove runoff water to a location that accepts hazardous chemicals, or neutralize it yourself by adding the mixture slowly to a bucket of 1 gallon clean water and 4 cups lime or baking soda.
Tips & Warnings
- When using plastic sprayers to apply acid to the garage, the acid may cause the sprayer to eventually stop working. Have a few extras on hand just in case.
- Muriatic acid can cause severe skin burns, blindness, chemical poisoning and permanent damage to property. Always take safety precautions seriously, and follow directions exactly. Make sure that a steady source of water, as well as extra baking soda or lime, is on hand to neutralize spills immediately.
- Work in well-ventilated areas.
- Do not dispose of unused muriatic acid in the bottle, and do not dump muriatic acid down sinks or storm drains. Neutralize the acid as described in step 8, or remove it to a hazardous waste facility.
About Acid Washing
Acid washing is a process of applying a diluted solution of hydrochloric acid (HCl), commonly referred to as muriatic acid, to concrete...