<p>A polymeric foam structure for use as a supporting pad for floor surface layers made from laminated flooring, carpet, tile, or other functional materials. The polymeric foam structure comprises a continuous band having increased density and consistent width along each side of the polymeric foam structure. The bands may have a flat surface or they may be optionally equipped with a plurality of peaks and valleys continuing along the band in an alternating grid pattern. The bands may be oriented so that the thickness step occurs from the same surface or that the thickness step occurs on opposite surfaces. The bands of increased foam density on the polymeric foam structure may be produced by a batch thermoforming process or continuous process comprising an apparatus having heated cylindrical rollers.</p>
