An Introduction to Concrete Processing

The concrete polishing industry is still in its infancy, but it's growing very rapidly. Although concrete polishing and other concrete processing steps have been performed for about 10 years, it has only been in the last two to three that architects, engineers, property owners, interior designers and general contractors have taken increased notice. Those contractors who get involved now and take time to understand the technicalities and variables of the process will be rewarded as market demands expand.

Growing pains

As with any other new or growing industry, there are challenges contractors must face. Some new contractors getting into the processing business think polishing concrete is simply flopping abrasives on and off the bottom of a machine. In reality the process is quite technical and when mixed with multiple variables beyond a contractor's control, results can potentially suffer significantly if a contractor does not have the proper experience and know-how to overcome these obstacles. There is also a slew of variables within a contractor's control that he or she also must learn to manage.

Additional problems in the industry include contractors who base their pricing on what other concrete processors are charging instead of basing their pricing on expenses plus profit. I also see a lack of formal technical training for contractors and a significant lack of understanding by the customer in what concrete polishing actually is.

To see the industry grow in the correct direction it's up to contractors to seek out the proper training, educate themselves on concrete processing as much as they can, and educate their customers on what proper processing means, the time it entails, and how much a proper job should cost.

It's really 'concrete processing'

With the concrete polishing industry still in its infancy, much of the terminology is used incorrectly.?"Concrete polishing" is frequently used out of context; most often the correct terminology is "concrete processing," which describes a process not much different from other industries putting material such as stone, metal and optical lenses through a like process.

Concrete processing is the act of changing an existing concrete surface by means of a mechanical process that involves cutting and/or refining the surface to a desired finish. Polished concrete is one of many end results in what is the processing of the concrete surface by mechanical refinement through the use of multiple abrasives measured in grits.

Currently, the industry breaks down the process of concrete polishing into grinding and polishing. Some within the industry simply use the word "polishing" for the entire process.?The process of polishing concrete consists of three consecutive categories: grinding, honing and polishing. Each category is then broken down into multiple steps, consisting of consecutively finer grit abrasives. During this process a densifier or hardener is applied that is absorbed into the concrete creating a chemical reaction that makes the concrete more dense and hard.

Not all processed concrete can be called polished concrete. For example, the grinding and honing category of steps results in a matte to a low, medium or high sheen appearance and does not go through the polishing category of steps.

Defining the categories and steps

Ground concrete is the lowest category of steps of a processed concrete surface. Any grit abrasive (if the abrasive medium is categorized in terms of grit) from approximately a 50-grit resin and below is considered a grinding step. A ground concrete surface has a flat appearance with no or very slight reflection and may at times have a low sheen.

Honed concrete is the next category of steps above ground concrete in the processing system. Any grit abrasive from approximately a 100-grit resin to a 400-grit resin is considered a honing step. A honed concrete surface has a matte appearance and/or slight clarity of reflection that has a low, medium or high sheen.