Molded fiber pans are also seeing some application as pan floor systems. These units are formed under heat and pressure form superior grade fibers treated to withstand the effects of weather and wet concrete. The individual units are easier to handle than the metal pans and , because of the smooth texture of the surface, these molded fiber pans do provide an attractive finish to the underside of a slab. The molded fiber pans do not have the life of the metal units but some contractors report up to 10 uses. Pan forms made of fiberboard, usually a corrugated cardboard type of construction. Fiberboard pan have several advantages. First, an infinite variety of sizes are available since flat sheets of cardboard can be scored so that they can be folded to the right width and length. Secondly, fiberboard pans are usually shipped knocked down so that shipping charges and storage problems are reduced to a minimum. The third advantage of the fiber pans is their adaptability. In case there are awkward shapes to fit, the fiber forms can easily be trimmed. A final advantage is the fact that they can displace more concrete than the systems that require battered sides.