How to Use CPC Classes and Levels to Specify Polished Concrete
Ryan Klacking, CPC Council Director
The Concrete Polishing Council (CPC) has been setting industry standards for many years now. Defining aggregate exposure and level of sheen in a systematic way has made positive changes and strides within the industry. Prior to this advancement, polished concrete was relayed in a format of steps, grits and the number of passes.
However, presenting a polished concrete flooring system by steps and grits left too many open opinions and potential cost changes that deviated from the required expectation. Owners, architects, and buyers of polished concrete had a difficult time obtaining what they expected or envisioned as well as being hit with cost changes that wasn’t understood.
Because of the CPC, there are now three (3) defined classes for aggregate exposure and four (4) defined sheen levels of appearance for polished concrete. A selection of Floor Class and Floor Appearance has allowed owners, architects, and contractors to standardize the polished concrete floor system. These advancements have been proven to increase adoption, predictability, and reliability in specifying or choosing polished concrete as the preferred flooring system. The CPC has also included language in the Aggregate Exposure and Appearance charts for verifying and testing the flooring system to validate that the installation meets the specifications.
Users of the Aggregate Exposure and Appearance chart will find a plethora of benefits. Firstly, when you specify the floor class and level, you’re specifying the overall aesthetic look of the floor you envision. For an owner, architect, designer or specifier this is the way to ensure your expectation is being met and you’re receiving proposals that align with the finished outcome. For a polishing contractor this is a benefit as you can master your recipe for achieving the floor class and level instead of focusing on following drafted means and methods that may or may not achieve the overall specified flooring system.
The CPC suggests that polished concrete flooring systems should be tested and judged by refinement which is measured prior to any penetrating, semi-penetrating or topical sealers. Testing polished concrete Distinction of Image(DOI), and haze level with a clarity meter ensures the owners are receiving a refined and durable floor that meets their expectations prior to any stain or gloss enhancing sealers. Many stain or gloss enhancing sealers can cover up scratches that were not removed due to improper floor processing as well as increase gloss or sheen levels. For this reason, the CPC recommends that the testing be completed prior to any sealer applications to ensure the floor has properly been refined.
It’s exciting to announce that the CPC will be releasing a technical document with the recommended instructions of how to properly set the test locations, how many test locations and how to pass, fail or troubleshoot polished concrete floors by testing measurables.