Polished Concrete Floors “Fact Sheet”
We have compiled this basic information “Fact sheet” from our experience over the years to help home owners, builders and architects understand the basic concepts behind “Polish Concrete Floors”.
This information is designed to help eliminate any possible problems that may arise once the concrete has been poured. Once the slab has been poured any issues become set in concrete.
As each project is different, this information should be used as a guide only. For more specific information relating to your project please contact myself (John Chapman) on Ph Mobile 0274 523 790 or office (09) 412 6217
Polished Concrete is a term used widely to define a style of concrete grinding to achieve a decortaive finish to the surface of the concrete. The application is used in domestic, commercial and industrial applications to achieve a desired finish for its useful purpose. It may be used as a “Decorative finish” for domestic applications or to harden, level and protect the surface for commercial and industrial purposes.
In general terms, the concrete surface is removed by diamond grinding about 1-5mm off the top of the concrete to expose the stone, pebble or aggregate that lays in the concrete. The surface is then polished or sealed.
Polished Concrete is widely used on both internal and external concrete surfaces. External finishes do need the application of an “Anti Slip” additive to any sealer coating system.
There are two different grinding methods to achieve a “Polished Concrete Floor”. These terms are called “Grind and Seal” and “Grind and Polish“.
The “Grind and Seal” method is very common and widely used. However it is not a true “Polished Concrete Surface”. Grind and Seal is when the concrete surface is ground back to achieve the desired stone exposure level. After the grinding process has been completed the floor is sealed with a high build clear sealer coating. These clear sealer coatings typically are made up of Acrylic’s, Urethanes or Epoxies. This system is generally cost effective. This system is more prone to scratching and damage caused by the hard concrete surface having no flexability under pressure.
The “Grind and Polish” method is when the concrete is ground back to the desired stone exposure level. A concrete densifier (typically Sodium, Potassium or Lithium based) is applied to the surface which reacts with the cement in the concrete. The result is a much harder concrete surface. The concrete is then honed (Polished) to a desired sheen or gloss level. A penetrating sealer is usually applied to protect the surface from stains. The result is a much harder, near scratch resistant surface with great light reflective characters. It is more labour intensive and costs more to produce however has much less ongoing maintenance costs.
We have samples of each of these processes to show and talk through the options and find out what you are wanting to achieve. There are advantages and disadvantages of both systems.
The Concrete grinding Process is made up of a number of different stages.
- First Stage Grind, (Aggressive Grind), usually completed at the start of the project to determine the amount of stone exposure required by the client. (Light/Medium/Full stone exposure) Completed just after pour (7-10 days) or prior to the exterior joinery being installed.
- Second Stage Grind, (Polish Grind) to clean the surface after the building process and prep the concrete for Sealing or Polishing.
- Slurry Coating, (Screed) applied to fill air bubbles which naturally occure in the surface of the concrete after grinding.
- Sealer Coatings, application of the surface clear sealer coatings for the “Grind and Seal” process.
- Densifying and Polishing process, for the “Grind and Polish” process.
We have more in depth information on each of the processes and stages of grinding should you wish to engage our company to complete your Polished Concrete project.