Polished concrete floors

If we are talking ‘flavor of the year’ in architectural flooring, polished concrete would have to be ‘it’.  Concrete flooring is relatively easy to install and is hardwearing, easy to maintain, cost effective, very sleek and will last a lifetime. This shiny concrete flooring looks great in all areas of the home including bathrooms and kitchens.

Concrete floor installation is categorized into two types: new floors and retrofit floors.

New concrete floors require less work resulting in lower costs, but there are a few things you need to be aware of so your new concrete floor can be polished.

First, the slab needs to contain a decorative aggregate.  The two most common aggregates are river stone and black basalt mix, however the aggregate can be almost anything you like.

Second, the finished surface of the concrete will need to be finished to a high standard to facilitate the polishing process. During the finishing phase any decorative aggregates such as seashells or car parts can be dropped into the surface of the concrete.

Note: the builder needs to be aware at the early stages of your job that you want polished concrete floors, so that the final finish is of the best quality.

Retrofit floors, or concrete resurfacing, can be done in two ways.  The existing floor slab can be cut (sanded) and the natural aggregate will be the feature (usually black basalt) or a toping slab with a minimum thickness of 2 inches can be added on top of the existing slab.

The first option is usually used as it will not reduce the finished heights of door openings and ceilings, however if a topping slab is used you have an option of aggregate finishes.

The process

  1. The concrete floor is cut 3-4 times depending on the finished surface and the desired aggregate exposure.  This can be done wet or dry, depending on the site situation, and will remove up to a quarter inch of concrete thickness.  If it is a new slab the cutting should occur before any walls are erected to ensure the best finish (it is harder to work around walls).
  2. The surface is then grouted with cement to allow imperfections and air bubbles to be filled.
  3. Two more cuts are done after grouting.
  4. A clear liquid hardener (indensifier) is then worked over the surface with a window squeegee.  The indensifier will provide a very glossy look to the finished floor and gives the floor extra strength.  The indensifier is worked into the slab for about 1 hour and will soak into the slab between a quarter and a half inch. This will require overnight curing before more cutting is applied.
  5. The concrete floor is then cut another three times – this is the final polishing stage.
  6. Lastly all the concrete floors are sealed with a stain and block out sealer to reduce water and oil staining.  The sealer will also reduce mould build-up in wet areas.

Concrete floors will not chip or dent like softer surfaces such as timber and are easy to maintain.  Mopping with warm soapy water once a week is the only maintenance required.

Cost of polished concrete floors

Polished concrete floors are relatively inexpensive when compared to other high-end floor finishes.