Editor’s note: In September 2013, the Concrete Sawing & Drilling Association (CSDA) released a first-of-its-kind technical document for the polishing industry. CSDA Standard ST-115 Measuring Concrete Micro Surface Texture provides procedures and benchmarks for measuring the surface texture of a concrete floor system. In this article, Andy Bowman, chair of CSDA’s Polishing Committee, describes the need for this standard and how it will change the industry.

This section of an aisle at a Nevada grocery store was reprocessed (repolished) using ST115 as a basis of refinement. The standard’s guidelines were used to audit each of the polishing steps to achieve maximum refinement at every tooling step.
Legacy Floor FinishingRenoNev. This section of an aisle at a Nevada grocery store was reprocessed (repolished) using ST115 as a basis of refinement. The standard’s guidelines were used to audit each of the polishing steps to achieve maximum refinement at every tooling step.

Aside from its glossy appearance, what sets a polished concrete floor apart from other types of floors is its function and durability. However, over the past several years, end-users have been experiencing durability issues that are tarnishing the reputation of polished concrete. Some floors are simply not holding their own.

When it comes to winning bids for construction projects, having a competitive advantage is often key. Many companies are successful at value engineering, in which they find ways to either improve their processes or reduce costs without skimping on quality. They either maximize efficiencies with innovative and proprietary tools, or they simply have a more organized labor force. Unfortunately, there is also a contingent of contractors who do not focus on turning over a quality project. Instead, they cut corners and race their competition straight to the bottom on price and quality.

Such contractors ignore surface refinement. They skip progressive grinding steps and don’t properly chase the scratch out of the surface. Many rely on topical concrete polishing sealers that have the ability to cover up heavy metal bond scratches and change the texture from rough to smooth. They can even increase the gloss number on projects that were tested with failing readings.

These “tricks of the trade” have caused end-users to spend much more than expected on maintenance systems to keep their floors looking as good as the day they were finished. We’re finding that the topical sealers are not sustainable and most of them are water soluble, meaning that most maintenance programs prescribed for polished concrete will remove the topical guard products. This causes floors to return to a pre-guarded appearance that may not have originally passed the gloss meter test.

In the past, the gloss meter has been used as a quantitative measurement device to give the end-user a quantifiable standard to write into a polishing specification. Plus, the facility owner was virtually guaranteed to get two things at once: a highly processed and refined floor, and a gloss level that’s easy to achieve with a resin-bonded abrasive tool.

With the emergence of products that can “fool” the gloss meter, though, concrete polishers and specifiers need additional ways to measure the refined surface for the value of its smoothness.