Sanding a concrete floor may be necessary to remove stains or to give the floor some extra texture before painting. You can also sand concrete in order to polish it to a high shine. Whatever the reason, sanding concrete can be a back-breaking and messy chore. Be properly equipped with the right tools before you tackle the job.
Clean the floors thoroughly before you begin sanding. Any particles or residue left on the floor will interfere with your sanding job and may scratch the floors. You will need a broom, a vacuum and a metal floor scraper. Scrape up any stuck-on debris with the metal floor scraper before you begin sanding. Then sweep and vacuum. Cover the vents with plastic sheeting to keep the dust from travelling through the house.
You have two options: a drum sander or an orbital sander. A drum sander is a large, electric floor-sanding machine that you stand behind and push across the floor. Some drum sanders come with a vacuum attachment that picks up some of the debris as you work. A drum sander is a good choice for a large project that requires extensive sanding. Because you stand behind the machine to use it, the drum sander is easier on your knees and back but is more difficult to control.
An orbital sander is a smaller, hand-held electric sander. You will get on hands and knees to work this sander across the floor. This type of sander is great for smaller jobs or for projects that require you to have a lot of control.
You may choose to use both types of sanders for your project. A drum sander can quickly sand the large portions of the room. You can then follow along with the orbital sander to sand the corners and any other hard-to-reach areas.
Sanding a concrete floor requires a variety of sanding pads. How many and what types of pads depend on the sander that you choose and the type of finish you are hoping to achieve. Each sander has a different series of sanding pads that are designed for use on concrete. You will start with a coarser-grit pad. Sand the floor once and then switch to a finer-grit pad. The finer the grit of the sanding pad, the more polished the floor will become. Purchase sanding pads that are compatible with the electric sander you use, and purchase a lot of the pads. Changing pads frequently often will result in a better finished product.
Wear a mask and goggles while working with a sander. Small particles of concrete can damage your eyes and lungs. Wear long sleeves and trousers to protect your skin.