Floor sanding is the process of removing the top surfaces of a wooden floor by sanding with abrasive materials.
A variety of floor materials can be sanded, including timber, cork, particleboard, and sometimes parquet. Some floors are laid and designed for sanding. Many old floors are sanded after the previous coverings are removed and suitable wood is found hidden beneath. Floor sanding usually involves three stages: Preparation, sanding, and coating with a protective sealant.
Preparation is the first stage of the sanding process. All nails which protrude above the boards are punched down. Nails can severely damage the sanding machines which are being used. Staples or tacks used to fasten previous coverings (if any) are removed to reduce the possibility of damage. Some brands or types of adhesives which have been used to secure coverings may need to be removed. Some adhesives clog papers and running gear of the machines used, and some can even make sanding impossible.
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 grits, so wearing a suitable respirator mask is recommended.
Sanding removes all patina, and can change the character of old floors.