Soft, Medium, and Hard Floors

Choosing the Right Tool for the Job

 By Brad Padgett

In the polished concrete industry, a slab is often established before the polisher ever even bids on the project. Admixtures that were introduced to improve the workability of the concrete mixture, and speed up or slow down the cure, can also reduce or increase the concrete density. The final condition of the slab is dependent upon these and other inert ingredients, the atmospheric conditions and the curing process, the results of which can range from a very dense, hard slab to a very porous, soft slab. The difference is dramatic.

Variable floor densities can have adverse effects on tooling, products, and even application methods. It is cost and time prohibitive to apply diamonds and chemicals to floors that they were not designed for. An overly dense floor will be very difficult to cut or grind and will not allow conventional chemical hardeners or final sealers to effectively penetrate the surface. On the other hand, a soft, porous floor will have a “punky” texture that will continue to soak up excessive amounts of conventional chemical hardeners or final sealers to the point that they hinder the product’s performance. 

Although varying in regions, medium or standard concrete makes up sixty to seventy percent of the floors encountered, and most of the products available on the market today are designed for this type of floor. Still, it is important to note that inconsistencies in concrete texture can occur within a single slab, even in floors with preferred levels of density.

To produce the best quality product available, Concrete Polishing Solutions enlisted the aid of a chemist to research various chemical make-ups of sealants and densifyers - adjusting the chemical composition and dilution rates to determine the most effective ratios. These differing mixtures were then applied to floors ranging in texture, structure, and curing climates across the country. The conclusions of this research found that though all elements are essential, viscosity was one of the largest variables involved in adequately treating difficult surfaces. 

Chemicals designed for dense concrete should have a low viscosity to allow the product to fully penetrate the tight surface. Chemicals intended for medium density floors were found to remain on the surface of dense concrete, rendering the product inept. The chemical hardeners found appropriate for porous concrete have a high-solid content to give structure, and hopefully, rebuild the cement paste. The higher solids help reduce the abrasion of soft concrete, thus further extending the life of the diamond tooling. The final sealer also needs higher solids to help fill the remaining pores and voids in the concrete, and to reduce oil, grease, and stain absorption.    

By observing diamond wear rates and repeatedly testing tools on variable surfaces, CPS also developed tooling and equipment specifically geared toward different floor densities. When choosing tooling, the bond compositions and the diamond exposure have a crucial influence on the tools performance. 

The diamond tooling required for hard concrete must have a bond or matrix that can easily wear away to continue exposing new diamond. The diamond itself should fracture during the grinding process to continually create a new edge. However, for porous concrete, the diamond tool should have a hard bond or matrix, so as not to release diamonds prematurely. Soft floor applications should utilize a diamond that is less likely to fracture, as fracturing would reduce the life of the tool on this surface. 

In 2005, Concrete Polishing Solutions introduced the Hard Floor Line, Medium Floor Line, and Soft Floor Line family of products to provide flooring professionals with supplies that reliably produce the highest quality cut rate possible. However, regardless of brand, using products designed for specialized applications will save time, effort, and reduce waste. Though the design of the tool or chemical may be completely different from one another, the methods used should remain consistent to produce a durable and long lasting polished concrete floor.