Did you know that the concrete slab underneath those expensive marble, granite and wooden tile coverings on floors can also be made to look like the elegant finishes they display at exceptionally lower costs and by a process that offers much respect for the environment?

The process of polishing concrete to produce an elegant polished concrete finish will eliminate the need for the overly expensive and high energy consuming marble and granite tiles, and even the wooden and vinyl tiles whose production processes disrespect our earth’s natural endowments. This renewed interest for concrete grinding and polishing is not only observed in Melbourne but elsewhere around the world.

Steps to Polished Concrete

The steps to produce polished concrete may range from a few steps to several elaborate steps depending on the level of quality desired for the concrete finish. Basically, there are only four major steps involved: surface preparation, surface grinding, surface sealing and surface polishing. Any additional step will just be a repetition of a major step to achieve the finer finish quality.

1. Surface Preparation

There are possibly two surface preparation types: one for a new concrete slab and another for an existing concrete slab. A new concrete slab will certainly involve less costs, since the mixing and the pouring of the concrete can already include some of the initial steps in polishing such as the addition of the decorative finish.

There is need to clean and clear the slab for any existing topping or sealer and to replace this with a new topping aggregate of at least 50 mm in thickness. This topping can contain the decorative elements you want to see on the final polished surface and is the equivalent to the topping that would hold the marble or granite tiles if these were to be used.

2. Surface Grinding

As soon as the topping has hardened and is ready to work-up, the grinding process begins with a 16-grit diamond grinding machine, and progressively repeated, each time increasing the fineness of the grit until it reaches the 120-grit metal segment. The low number code in the diamond grit indicates the coarseness level at which the surface is to be scraped or ground. Judgment is needed as to how many grinding cycles are to be repeated. Increasing the grit number refines the concrete surface to its desired smoothness.

The grinding, and consequently the polishing, can be done either dry or wet, although the wet method is gaining more popularity in obvious avoidance of the adverse effects of the dust powder on our health.

3. Surface Sealing

During the grinding process, and prior to the polishing, a sealing solution is applied to fill up any cracks, holes or distortion that may have been created on the surface from the initial grinding. Likewise, a densifier hardener solution is added to the concrete surface to further solidify and strengthen the surface as it is subjected to polishing. A densifier is a water-based chemical solution that penetrates into the concrete and increases its density to make it liquid-proof and almost scratch-proof due to its newly acquired abrasion resistance.

4. Surface Polishing

After achieving the surface smoothness level from the metal grinding, the polishing begins with a 50-grit diamond resin pad. The polishing cycle is repeated progressively as in grinding, except this time various increasing grit level pads are used. Suggested grit levels after the first 50-grit are 100, then200, 400, 800,1500 and lastly 3000 grit. As in the grinding, judgment is needed as to the final grit level to be used. What is important is that the concrete achieves a gloss that is comparable to most commercially available surfaces.

The Polished Finish

Polished concrete is increasingly becoming the more popular floor finishing option nowadays not only because of its economy in application but also its evident sustainability feature. It is considered a green solution. Additionally, polished concrete is a low maintenance finish. It is easier to clean. Due to its acquired impervious quality, it is impenetrable by most liquids. With just a soapy water on a weekly round, it can be kept to its original sparkle and gloss. Polished concrete also has life span that is longer than most other finishes.

Most notably, polished concrete comes in several beautiful designs that can match or compete with designs of commercial expensive tiles.