These days, homeowners often choose to have exposed concrete floors on the first floor of their homes. This is because concrete floors are very easy to clean and can be attractive if done properly. But before you can apply colored stain and a wax or urethane coating to your concrete floor, it has to be carefully prepared. This involves using a sander and varying grits of sandpaper to remove any stains, discoloration, paint or minor damage from the surface.
The Equipment You'll Need
You'll need to rent a professional grade sander. You're also going to need sandpaper discs (course, fine and superfine). You'll be fitting these discs onto the sander, switching them out depending on how much sanding a particular spot requires. You're going to need plastic sheets and plenty of tape to cover any walls, fixtures or fixed cabinetry so as to protect them from the floating dust. Also protect yourself by wearing goggles and a dust mask.
Before you can start sanding, all the furniture needs to be removed from the room. Then vacuum the floor thoroughly to get up any loose debris or dirt. Make sure that you cover everything else (except the floor) with plastic sheeting. Follow the instructions that came with your rented machine to put on the sanding discs. Some have to be attached, while others will simply stay in place because of the weight of the machine.
Using the Right Sandpaper
Which sandpaper you use at a particular point of the process depends on how much sanding has to be done. For basic stripping and sanding, use coarse sandpaper in the 40-60 grit range. To get rid of minor damage and to create a relatively smooth finish, switch to 80-120 grit. Finally, if you want a perfectly smooth finish, use 200-400 grit sandpaper. If the area you have to sand is fairly small, you could just use an orbital sander or even a palm sander. If there are serious imperfections in the concrete, it may be necessary to rent a concrete floor grinder equipped with a diamond disc.
As You're Sanding
To begin sanding, position yourself at one corner of the room and do the sanding in four foot square increments. Complete one section and move on to the next. When you're finished, use a broom and dust pan to clean up all the dust you created. Then go over the floor again using the fine or superfine disc to get things smooth. Now take a close look at the floor to see if you've gotten up all the imperfections and stains you wanted to remove. If not, repeat the process. When you're finished, mop the floor and let it dry completely before you start applying any coatings. Talk to people like Robar Enterprises Inc, for more information.