A method for manufacturing a flexible, extruded plastic wall base with a hollow core is presented. The method includes using extrusion die for heating and extruding plastics using a multi-functional insert within the die and air pressure to create a hollow core in the wall base. The hollow core allows less material to flow though the die so that the die stays hotter and the flow of the extruded plastic is not impeded. The resulting extruded plastic wall base is comprised of a generally thick portion, a generally thin portion and a profile on the face or front of the wall base.