Abstract: A method and apparatus for the construction of a flooring system for use at a construction site such as an oil well drilling site. The flooring system is formed by interlocking a plurality of flooring units. Each of the flooring units includes a rectangular base section and a surface section attached to and overlaying the base section. One end of the rectangular base section is aligned with one end of the surface section which has at least one open-ended locking slot along its length. Located on the opposing end of the surface section is at least one locking tab formed from the surface section and projecting beyond and above the edge of the base section. The locking tab is aligned with the locking slot of the flooring unit. The method of constructing a flooring system utilizing such units includes positioning one unit, with the use of a lifting device such as a crane, adjacent to a second flooring unit and inserting the locking tab of the first unit into the adjacent second unit.