Pros & Cons of Acid Stains

by Daniel Owen - R&D Leader, Specialty Flooring

Pros & Cons of Acid Stains

In the world of architectural concrete, your coloring method can have a major impact on aesthetics and longevity. So how do you know if acid staining is the right choice? We’re breaking down the pros and cons:

Pros: Acid stains have been around for more than 50 years and is the most popular methods for applying topical color to existing concrete slabs.

Personally, acid stain is one of my favorite coloring methods. It will provide you with a wide range of tones, from soft and muted earth tones to strong and deep earth tones. Additionally, it will almost always display subtle variation in just one application. 

Cons: In my opinion, the biggest drawback is the fact that every slab takes the stain differently. The age and mix design of the slab is a key factor in the outcome of staining variations.

Some slabs may only have variations of a shade or two while others can be very drastic. I have seen jobs with multiple pours and the stain turned two completely different colors, even though the same color and method of application were used throughout the entire project. This is, of course, an extreme example. While it isn’t the norm, it is something you should be aware of.  More often than not, the color will only be off a shade or two. Since acid stain usually produces a floor with a lot of variations in tone anyhow, this isn’t always an issue.  

Another factor is the amount of time and labor associated with the actual staining process. A large part of the labor includes rinsing and neutralizing the slab once the stain is applied. The stain leaves a physical residue that must be completely removed prior to the installation of the sealer.  

The final factor to consider is the lack of colors. Depending on the manufacturer, you will have six to 10 colors to choose from, and nearly all will be earth tones.