Comparing Polished Concrete

Posted by Steve Perfect

“Polished Concrete is Not Purchased in A Box at Depot R’ Us”…. Unfortunately for the buyer, this means competing contractors are often unlikely to be installing Polished Concrete utilizing similar materials & processes, therefore, the buyer is receiving differing quotations on Polished Concrete that will truly yield different results. I.E. The buyer cannot go to Depot R’ US, purchase Polished Concrete and pay someone to install the product. The manufacturing plant for Polished Concrete is literally brought to the buyers’ building and installed in the format that the individual concrete polishing contractor deems feasible. One contractors’ ideal polished concrete system more often than not, is not identical to that of another polished concrete contractors’ system.

The easiest fashion for the Polished Concrete buyer to compare ‘apples to apples’ bids is to utilize a manufacture specification in the bidding process. This is a subject that was covered prior, see Industry Dilemma . However, this article is not meant to dwell on prior topics but instead outline what buyers’ need to look for when receiving various Concrete Polishing quotations.

Foremost, lets cover the main differentiating factors that cause contractors to yield different results (on the same floor).

Equipment

The mechanical polishing of concrete requires heavy grinding equipment affixed with diamond tooling run in sequential order. As with any industry, there is a multitude of manufactures producing concrete polishing equipment for contractors to utilize. The different equipment varies drastically in width of grinding path, weight and speed in which the tooling (aka diamonds) rotates. While width of equipment may alter a contractors pricing due to their ability to cover larger areas in less time, the weight of the equipment will produce different results than lighter equipment no matter the width. The more weight on the diamond tooling, the better the final polished concrete result will be. The speed the equipment allows the diamond tooling to run will also differentiate the final polish. Variable speed is of utmost importance, in many scenarios a concrete polisher will have best results running they’re initial ‘grinding’ diamonds at a lower rpm and upon the polishing or ‘resin’ diamond stages- higher speeds result in a better final polish. The overall rpm that a variable speed machine is able to obtain is going to differentiate the final result of the polished concrete.

Diamond Tooling

The concrete polishing process utilizes many different diamond tools, run in a sequential order below the machine on the concrete surface (comparable to wood sanding but with a higher count of stages). As with the equipment, there again lies a multitude of manufactures marketing different diamond tooling options. Though the grit levels (grit being the diamond grit size for a specified tool) are likely similar, the metal or resin bond material that holds them together is not. Also, the diamonds that are molded into polished concrete tooling are of highly differentiating qualities between manufactures, again playing a hefty role on final polished concrete finish. Combine tooling variables with different equipment manufacture machine weights and speeds- there is an endless array of results that come to a buyers’ floor.

Chemicals

The polishing process utilizes various chemicals in the contractors’ said concrete polishing process. A main factor being the densifier. Densifier is used to harden the concrete surface by chemically reacting, filling pores and increasing surface density. There are many types of silicate densifiers; lithium, potassium and sodium. All said lithium types are efficient in hardening concrete based on the concrete’s original hardness and the point in the polishing process in which they are applied. I.E. A potassium densifier would typically be used on an abnormally soft concrete surface or after the grinding (metals) process, prior to the polishing (resins) process. A lithium densifier would typically be used on an originally hard concrete surface and latter in the polishing process. Better said, potassium is a thicker silicate carrying agent that allows the chemical to dwell on a porous (soft) surface while the lithium is able to sufficiently penetrate overly hard (less porous) surfaces. Again, countless manufactures produce said densifiers- creating a field of variances of chemical quality. More so, the point in the polishing process that the contractor utilizes the densifier, can vary the overall result of the final polished concrete floor.

The Polishing Process

As if the differences of equipment and chemical weren’t enough to differentiate the buyer’s polished concrete floor, manufactures and concrete polishing contractors alike share differed beliefs on the sequential diamond passes and at which point to apply chemical. In recent years, two main forms of mechanical concrete polishing systems have come to be: Traditional & Transitional. Click pictures below to see systems.

Aside from the main differences of the two systems, contractors are adjusting which steps to ‘jump’ and wherein densification occurs. This ultimately results in a different polished concrete resul. It should be noted in regards to the transitional system- various manufactures have contested that the creation of the transitional diamonds were not intended to ‘jump’ steps but merely gain efficiency and longevity of the diamond tooling itself while processing in the traditional manner. Either way, there is a large number of newer manufactures and contractors boasting that they’re ‘transitional system’ is equal to, if not greater, than that of the latter traditional.

Keep posted for the secondary article of this series which will cover how to differentiate what your contractors are offering and efficiently comparing their price points.