Concrete polishing is a process of smoothening out a concrete surface. It involves mechanically grinding and polishing concrete using abrasion to brush the concrete surface. The concrete is also treated with a penetrative chemical known as a hardener. The hardener penetrates the concrete in a chemical reaction and hardens it making the surface dustproof. The main tool used is a diamond bonded on grinding discs attached to a concrete grinder.
Dried concrete tends to be rough on the surface. When used as a floor or counter, it has an undesirably rough texture and often requires further finishing, either in form of tiles, or a cement-sand screed. Concrete polishing is a finishing technique that smoothens the concrete surface by evening out the tiny bumps that make the surface rough. This eliminates the need for further finishing techniques like tiling. Concrete polishing not only makes the concrete surface smooth but it gives it a nice shine. It also makes the floor dust and waterproof.
Concrete polishing can be done through the following process.
Surface preparation; This involves preliminary activities of preparing the surface for polishing by sweeping off any existing dirt, dust, and debris. Any mud stains are also scrabbed off to leave the concrete surface clean and bare.
Removing existing coating; After the dust and debris has been removed, the existing coating is also removed by scarapping it off, or scrubbing depending on the difficulty in removal. This is mainly done for an already existing water proofing membrane in preparation for a fresh water proofing membrane.
Filling cracks; Any existing cracks and joints are patched up and filled with semi-rigid filler. One such filler is polyurea joint filler. For parts of the roof that are severely damaged, more repair might be necessary. For example a big patch on a concrete flat roof slab might require recasting of concrete on that particular area.
Grinding; This process is similar to sanding the surface of wood with sand paper, only this time, a grinder is used instead of sand paper. This is done to even out the surface and making sure all patched up areas are in the same level. This is done using a metal bonded diamond grinder of between 30-150 grit.
Hardener; After the initial grinding, the hardener is applied to the concrete. This is a chemical that enhances the concretes surface by hardening it and making it more resilient. Concrete hardeners are are rich in silica or soluble silicates that chemically react with calcium hydroxide in concrete to produce a stronger and denser concrete surface.
Final polishing; Polishing is the same as grinding, the only difference being that a grinder of higher grit is used. The is done with a higher grit resin bond, between grit 100-3000. A higher grit value produces a finer surface.
Pros and cons
A well-polished concrete floor is smooth and dust-proof. That’s because it is smooth and can’t easily retain dust. This makes the concrete surface easy to clean and maintain.
A well-polished surface is also waterproof and doesn’t easily get wet and damp. This also makes the surface easy to maintain because it doesn’t attract moisture or facilitate the growth of fungi.
A polished floor is shiny and thus reflects light. This makes a room well-lit even with minimum artificial lighting thus there is a reduced lighting need. This reduces expenses for lighting and energy expenditures.
The shininess of the floor also enhances a floor aesthetically and makes it look classy.
Polishing a concrete surface increases its longevity because it makes the surface more resistant to moisture and dirt.
It eliminates the need for any other form of surface finishing like tiling. Such a floor has all the qualities of a good finishing; smooth, beautiful impervious to dirt and dampness among others.
The downside of polishing a concrete surface is the inherent costs involved in the process. Concrete polishing requires tools like concrete grinders which use diamond-coated grinding discs which are costly.
Concrete polishing is another form of floor finish that involves smoothening out of a concrete surface giving it a smooth texture and shiny look. These are the few facts one ought to know before considering it as a floor finish option.