A poured, seamless polyurethane floor includes woodgrain markings and floorboard markings protected within a top clear coating, thereby to achieve a poured seamless floor with a “wood look.” The woodgrain markings are achieved by moving a heavy brush through the wear layer, during installation, prior to curing. The longitudinal floorboard markings may be achieved by moving a line marking apparatus over the upper layer, parallel with the woodgrain markings, after the wear layer has cured. The line marking apparatus assures distinct parallel floorboard lines on the wear layer, due to the use of permanent markers held in a downwardly biased, spring-loaded condition during movement of the apparatus over the floor. The installer then marks the transverse floorboard lines. A top coat seals and protects the woodgrain marking and the floorboard lines, thereby resulting in a seamless, poured polyurethane floor with a permanent wood look.