Concrete sander: tips for purchase and use

As the name suggests, a concrete sander is specially developed for sanding concrete and making concrete floors flat and smooth. It is also used to remove old coatings and glue residues. Concrete sanders work with a rotating disc to which diamonds are attached. The grit size of the different diamond discs varies from 16/20 for coarse sanding to 140/150 for fine polishing.

Concrete sanders are classified into two primary types: those with wheels and a handle, similar to a lawnmower, and hand sanders. Partly because of the price, the first category is only interesting for professionals. For DIY enthusiasts, a considerably less expensive hand sander typically suffices perfectly well. When it comes to a one-off job, renting a concrete sander makes more sense than buying it. But if you decide to purchase one, you have a tool that will come in handy for more jobs than just sanding concrete floors.

There can be several reasons for sanding a concrete floor. For example, to remove glue residues and old coating or epoxy layers. The fine scratches caused by sanding with diamond grains also act as an ideal base for the adhesion of a new coating or adhesive. Sanding also serves to level the floor and remove bumps. You can sand away stains and dull spots with a concrete sander. Additionally, you can flatten a new concrete floor that is too rough and polish the floor smoothly for an aesthetic effect.

The possibility to mount different sanding discs makes a concrete sander also suitable for materials other than concrete. You can clean natural stone and paving, remove old paint from walls and remove lime plaster and graffiti.

The main hazard when using a concrete sander is the irreversible release of dust, which poses a significant health risk. Therefore, always utilize a machine equipped with a dust collection bag or one that can be connected to an external vacuum cleaner. Read more about dust-free working with power tools in ‘Which dust mask for which job?‘