Concrete Grinders Versus Polishers

The terms ‘concrete grinder’ and ‘concrete polisher’ are used interchangeably but they actually perform different functions.

You could call both concrete grinding and concrete polishing part of a ‘concrete processing’ procedure whereby the existing surface is changed by using machines with multiple abrasives to refine the surface in stages to achieve a desired finish.

‘Concrete processing’ involves three consecutive categories, namely grinding, honing and polishing with different machines used for each stage.

Polishing concrete comprises all three stages with each stage broken down into multiple steps.   It can be time-consuming and labour-intensive because it can take at least 10 to 15 steps to be done properly.

A concrete polisher is used to mechanically grind the surface to first expose the aggregate, with progressively finer diamond abrasives used to further grind the surface down.  After all the stages, the concrete is finally sealed with a penetrating densifier to harden the surface and give it a satin or gloss finish.  The end result of polished concrete surface is totally smooth and virtually glass-like.

Honed concrete is generally a faster and cheaper alternative to polished concrete with the number of processes reduced by up to 60%.  A concrete grinder is used to grind the surface to remove as many scratches and uneven areas as possible and to get the desired exposure.  A clear coat of penetrating sealer is then applied for a more natural look.  In industry terms, this process is called ‘grind and seal’.

So, it’s not a case of one type of machine versus the other.  A concrete polisher isn’t ‘better’ than a concrete grinder - they simply do different things.

The trick is to get the right machine for the particular job that needs to be done.

It’s also easy to get confused between the two machines, especially as there are so many different names for the various finishes and looks.   Two cut and seal.  Non reveal.  Cappucino.  Salt and pepper.  These are just some of the industry terms for different concrete grinding and polishing processes - and unless you know exactly what look you’re after, it’s best to come and talk to an expert to make sure you get the right equipment with the right tooling to achieve the desired outcome.

A concrete grinder is typically used to:

  • Remove glues, coatings (eg old paint), membranes etc
  • Smooth out high spots, scratches, chips, bumps, lumps etc
  • Prepare concrete slabs for new floor coverings and paints

A concrete polisher is used to grind the floor to a desired gloss level using progressively finer abrasives measured in grits.  These pads comprise tiny bits of diamond embedded in a metal or resin disc which rotate horizontally to smooth and polish the surface of the floor.  Initial grinding usually starts with a coarse 16 or 30-grit diamond and ends with a 1500 or 3000-grit diamond, depending on the level of gloss that’s required.

Both machines come in different sizes, from small, handheld ones to heavy duty ones for industrial projects - and all can be fitted with vacuums for effective dust control.

And just when you thought you’d got a grip on the differences between the two machines, here’s one that does BOTH jobs! 

The large 415V Planetary grinder is ideal for grinding, honing and polishing concrete floors in large-scale residential and commercial projects, both indoor and outdoor.  It also comes in an LPG version which runs off a gas bottle, making it a convenient option where access to power is restricted. 

Concrete equipment hire is a godsend when it comes to DIY flooring projects, but it’s imperative that you get the right piece of equipment for the desired end result.  Whilst it does take a level of expertise to operate these machines, here at Concrete Hire, we’ll explain everything and guide you through the process with our comprehensive ‘step-by-step’ set of instructions.  We’ll also ask all the right questions to make sure that any concrete equipment you hire from us is appropriate for your particular project.

To see our full range of specialised concrete equipment for hire, including grinders and polishers, click here or chat to one of our friendly team on 0418 222 273.