If there’s an accident and an acidic substance spills on concrete, it makes an ugly stain and exposes the surface to further damage. Repairing acid damage is a viable solution to restore the look and durability of your concrete without total replacement.

Learning about what acid does to concrete prepares you to find the best solution to your situation.

In this article, we’ll explain how the process of repairing acid-damaged polished concrete is carried out and discuss the types of buildings most susceptible to such damage.


Polished Concrete and Acid-Damage

While polished concrete is extremely resistant to most liquids, acidic ones can etch the surface. This is a reaction similar to the way a marble countertop dulls if you spill lime juice on it.

Concrete has a pH of 11 or higher, while acids capable of damaging it have a pH of 4 or lower. Although acids are highly reactive upon contact, they tend to neutralize themselves.

As a result, the damage caused by acid is typically concentrated near the surface of the concrete rather than deep within it. Therefore, if you repair the stain quickly, the problem won’t worsen.


Buildings Prone to Acid Damage

Certain buildings are more exposed to acid damage on their polished concrete floors. Liquor stores, grocery stores, and auto repair shops are particularly susceptible due to the potential for spills of acidic liquids.

For instance, a broken bottle of red wine can cause damage in a liquor store. In a grocery store, acidic substances like vinegar, tomato paste, or sodas can lead to etching on your polished concrete.

In an auto shop, battery acid poses a significant hazard. Most polished concrete protections don’t stand up to sulfuric acid found in car batteries.


Is Professional Repair Necessary?

When it comes to acid-damaged concrete repair, it’s essential to entrust the task to experienced professionals, especially when aesthetics are crucial. Using overly aggressive diamond tooling can do more harm than good.

Skilled blending techniques and knowing when to stop grinding deeper are critical factors that only an experienced restoration professional can handle effectively. It takes a delicate touch, requiring years to master and make an invisible, long-lasting acid damage repair.


Repairing Acid-Damaged Concrete Process

The process of repairing acid-damaged concrete involves several steps, such as:

  1. Determining the appropriate starting diamond grit to remove the acid damage is crucial. Using too coarse of a grinder can create scratches that require extra repair work.
  2. The process starts with a fine grit and progressively moves to coarser ones to identify the proper starting point. Each pass requires drying time to reveal blemishes, as wet floors can hide imperfections.
  3. Using the determined starting grit, wet diamond grinding commences, removing the damaged concrete. Wet grinding is essential for safety reasons and to address concerns related to silicosis.
  4. Multiple passes with finer grit diamonds are performed to eliminate visible scratches and ensure a cleanable floor. The concrete slurry is removed from the slab through auto scrubbing.
  5. After the floor is clean and dry, it undergoes chemical re-hardening and dust-proofing. The chemical must remain wet for 20 minutes and should be applied until the floor rejects further absorption.
  6. Optional Steps: Burnishing the floor with a diamond-impregnated pad and stain guard application are optional. Burnishing increases gloss and cleanability, while stain guard provides protection against oil spills.