Abstract: Lightweight, structurally integral, and strong composite rack shelving that includes a shelf. The shelf includes a honeycomb core sandwiched between an upper skin and a lower skin so as to form a composite structure that is lightweight and strong. The shelf has a plurality of through bores that pass vertically therethrough which allow flames under the shelf to pass upwardly therethrough instead of sidewardly therealong and to pass an extinguishant thereabove to flow downwardly therethrough for extinguishing the flames thereunder.