The invention relates to a method for producing polyurethane foam slab stock, according to which the reactive components polyol and isocyanate are transported to a mixer in metered doses, are blended in said mixer, subsequently discharged from said mixer and applied to the base paper. The method is characterised in that once the reactive mixture has left the mixer, it traverses a distribution unit that is situated directly above the base paper, the flow velocity of the mixed fractions that are discharged at the edge of the distribution unit in essentially a transverse direction to the transport direction being higher than the flow velocity of the mixed fractions that are discharged at the front edge of the distribution unit essentially in the transport direction and the reactive mixture exits the distribution unit in the form of a film, only the upper face of which forms a boundary surface with the surrounding atmosphere.