It wasn’t so long ago that polished concrete floors were something more likely to be seen in a shopping mall or art gallery, rather than inside the home. But times and trends are changing, and now polished concrete floors are becoming a popular choice in residential construction.
After all, a durable, hassle-free floor that requires little maintenance is a good selling point. But are polished concrete floors everything they’re advertised to be?
There seems to be some confusion that a polished concrete floor costs less than other flooring options. It’s easy to see why. The concrete is already there, so to lay timber or carpet or tiles over the top must cost a lot more, especially with all the extra materials required. However, this isn’t necessarily the case.
There are typically three different ways a concrete floor can be polished, and they all vary in price. From least expensive to most, they are: grind and seal concrete, honed concrete, and mechanically polished concrete. Each method requires specialist equipment and sandpapers and will be affected by the design of the building. Small spaces and rooms with lots of angles are more difficult and take longer, which increases the price; in some cases, additional equipment will be needed to get into these areas as concrete polishing machines tend to be quite large. The complexity of your floor will also vary the cost. By complexity, we’re referring to the visual appearance of the floor. A polished grey concrete floor is the simplest because it requires less grinding and forgoes any specialist aggregate; exposed aggregate floors can differ in the amount of work required.
A uniform pattern with the same aggregate is the most simple, while intricate patterns with different coloured concretes and aggregate can really reach into the higher ends of technical difficulty and price.
In either case, the top layer of your concrete floor has to be ground off to expose the aggregate so that it can be polished. This raises another issue that can affect the price of a polished concrete floor. So that the floor can be polished evenly, the floor needs to be level. Any deviations in the concrete, such as humps or troughs, need to be addressed before the polishing can begin and requires additional materials and work hours.
Grind and seal method. This is the least expensive way to polish a concrete floor and involves grinding the floor back until it is flat and smooth, either exposing the aggregate or leaving it plain. After the grinding process, a non-penetrative sealer is painted on top of the floor to give a polished look. This sealer will wear off over time and will need to be refinished every few years.
Honed concrete. Similar to the grind and seal method, but the sealer used penetrates further into the concrete. This means the polished look lasts longer and doesn’t need to be reworked as often.
Mechanically polished concrete. This involves grinding the floor back and then adding a densifier to the concrete, which helps to harden it. The floor is then polished with different grits of fine sandpaper to the desired effect. While this is more labour intrusive and costs more, it is possible that this method may work out to be economical over time because the appearance of the floor lasts longer, and the floor is considered to be more durable.
Although it is best to decide on a concrete polished floor before a slab is poured, ensuring the right hardness of concrete is used and the slab surface is worked as flat as possible, existing concrete floors can also be polished providing the slab is level and in good condition. To gauge an overall cost, it would be best to get quotes early and compare these to the cost of other flooring options.