Abstract: An integral reinforced resin grating structure having a plurality of load bars having a height dimension and a neutral axis and a plurality of cross bars integrally connected with said load bars. The cross bars may have a height less than the load bar height. The upper surface of the cross bars may be flush with the upper surface of the load bars. The lower surface of the cross bars may be located near or above the neutral axis of the load bars. The cross bars and load bars are reinforced with rovings placed along their respective longitudinal axis. The load bars have longitudinal rovings placed below the lower surface of the cross bars. Above the lower surface of the cross bars, the load bar rovings are interwoven with the cross bar rovings.For improved plastic reinforced grating structures having increased surface hardness and abrasion resistance, tabular alumina or other materials having a Mohs hardness of approximately 7 or higher may be added to the resin.

Abstract: A height compensating device made from a non-toxic material defining a support surface of a predetermined shape and having a periphery with a sidewall extending downwardly and outwardly from said sidewall. The surface of the support surface is roughened to the roughness of a quartz number 4 grit or greater. The structure has a weight of 8 pounds or greater.