A variety of floor materials can be sanded, including timber, cork, particleboard, and sometimes parquet. Some floors are laid and designed for sanding. However many old floors are also sanded after the previous coverings are removed and suitable wood is found hidden beneath the old coverings. Floor sanding usually involves three stages: Preparation, sanding, and coating with a protective sealant.
After the floor is prepared, the sanding begins. The first cut is done with coarse-grit papers to remove old coatings and to make the floor flat. The differences in height between the boards are removed. The large sanders are used across the grain of the timber. The most common paper used for the first cut is 40 grit . The areas which cannot be reached by the large sanders are sanded by an edger, at the same grit paper as the rest of the floor. If filling of holes or boards is desired this is the stage where this is usually done. 80 grit papers are usually used for the second cut. The belt sander is used inline with the grain of the timber in this cut. A finishing machine is then used to create the final finish. The grit paper used is of personal preference, however 100-150 grit papers are usually used.
The sanded floor is coated with polyurethane, oils, or other sealants. These are often highly poisonous, so wearing a suitable face mask is recommended.
Sanding old boards sometimes exposes worm eaten cores, effectively ruining the floor's appearance. This can reduce the sale price, or even cause the floor to need replacement.
Sanding removes significant material, and timber floors have a limit to how much they can be sanded.