Concrete & Cement Diamond Polishing












Here below are some of the most common questions regarding polished floors, concrete floors and cement floors. If you have specific questions and can't find an answer below, please email us and we'll get back to you with an answer.

                  - Can all concrete slabs be diamond polished?


- No. Most concrete ever poured was not meant or, let's say engineered for diamond polishing. In most cases when diamond polishing we are looking for concrete that is in "sound" conditions, meaning concrete that can maintain its structural strength and integrity during the grinding and polishing operation. Only in a few cases we encountered floors that could not be directly polished. In such a situation, if strengthening products are not enough, a cement overlay can be applied (after structural repairs are performed) or a new concrete slab can be poured prior to polishing. Thanks to new technology we can now repair moving cracks, control joints and expansion joints during the polishing operations.



- Is polished concrete slippery?


- No. Because of the invisible micro-scratch pattern left by the diamonds polished concrete surfaces are extremely safe when dry. When a floor is wet (that's valid for any hard surface such as ceramic tiles, epoxy coatings, linoleum floors, hardwood, laminate, VCT...) it can become more slippery. The industry standard final grit for polished concrete floors is 800, which on most concrete slabs produces a medium-high reflectivity and a very smooth, safe surface. In premises open to the public it is important to use "wet floor" signs to make users aware and possibly close wet areas to traffic. Since the California building code it is not specific on the parameters that make a floor "slip safe" but only states: " Floors and ground surfaces shall be stable, firm and slip resistant" (CA Building Code section 11B-302.1) it is difficult to determine if a floor is safe or not. The ANSI (American National Standard Institute) established some guidelines on what parameters to consider when determining slipperiness of floors, which in general depends not only on the floors, but also on the method of drainage, the shoes worn by users and other factors. In other words, the same highly reflective polished floor may be safe for a person wearing threaded sole shoes but not safe for a user with smooth sole shoes. ANSI also establishes the coefficient of 0.42 as a minimum safety standard for wet floors. A measurement can be performed with electronic and/or mechanic instruments to determine the specific coefficient of slipperiness on a specific floor



- Does standard concrete cracks?


- Yes. Portland cement based concrete is susceptible to cracking because it tends to shrink while curing. The curing is the chemical process that happens in the 4 weeks after concrete is poured and that allows concrete to gain strength. Concrete is a peculiar material that tends to increase its strength when compressed and becomes weaker when stretched. The internal forces developed in concrete when shrinking are causing points of weakness in the slab, which ultimately can become cracks. The best way to address the cracking is to install “control joints”, which are grooves or cuts every so many feet. These grooves are installed as soon as it is possible to walk on freshly poured concrete. They cause the concrete to become weak right in the bottom of the groove, and that’s where the crack will appear, but it is hidden from sight. In this way, control joints do not prevent cracking, only allow for cracking to happen in places where it can be hidden from sight.



- Is there any concrete that will not crack?


- Yes. A new type of concrete has been recently developed (Type K concrete). This concrete mix contains an additive that transform the concrete from a shrinking material into an expanding material. When this additive (CTS Komponent) is added to standard mix in conjunction with steel reinforcement or reinforcement fiber, the expansion in the concrete is transformed in compression force, which ultimately makes the concrete crack resistant. With Type K concrete control joints are installed every 100 feet, making most residential floors free from control joints.



- Is all polished concrete high sheen?


-No. Whenever a lower sheen/reflectivity is desired the polishing process can be stopped at a lower grit. This will not affect the performance and durability of the floor surface, but higher reflective surfaces are smoother and a bit easier to clean. The lower reflectivity finish (Honed Finish) is usually obtained at 100 or 200 grit and produces a lower reflectivity,  matte or satin. In this floors the light from light sources (windows, ceiling lights…) will still bounce off, but not as mirror image.



- Does polished concrete easily scratches?


-No. Because of hardening produced by the diamond abrasion and also because of the final burnishing that is performed on diamond polished surfaces, Polished Concrete (as well as Polished Cement and Cement Terrazzo) are extremely resistant to scratching. Diamond polished floors are mold resistant, dust resistant (they will not accumulate dust) and can also be treated to be water and oil resistant.



- Does polished concrete require maintenance?


- Yes. As any other floor, polished concrete will require a certain amount of maintenance. High traffic floors (restaurants, retail centers, public buildings…) will require maintenance more frequently than residential floors. The biggest advantage of Polished Concrete and Cement surfaces is that the maintenance is very quick and more cost effective than for any other floor. On residential surfaces diamond polished floors may require a maintenance intervention as little as 5 years. The standard maintenance operation consists of re-application of protective sealer and buffing/burnishing.



- Does diamond polished concrete/cement require a protective sealer


- Yes. Unlike standard concrete, polished concrete can be burnished. This operation consist of the application of a penetrating clear sealer in a very thin layer and then buffing the surface with a high speed burnisher equipped with diamond encrusted pads. This operation generates heath, which chemically activates the sealer, producing a surface very similar to a glaze. This makes the already hardened surface extremely resilient to scratching and wear, also increasing the sheen. This process does not diminish the slip resistance of the floor. This operation is unique to diamond polished surfaces, and it is crucial to the proper performance of the floor.