In architecture, a floor is generally the lower horizontal surface of a room, and/or the supporting structure underneath it. A floor typically consists of a support structure called a sub-floor on top of which is laid a floor covering to provide a walking surface. The work of installing a floor covering is called flooring. This term is also used to refer to any permanent floor covering and in particular to wood flooring. The various levels in a building are also called floors. See storey for t… (More on Flooring)