Abstract: Calcium hydrosilicate bound fiberboard, in particular double-deck board, is manufactured in a process wherein a fiber-binder-filler mixture having a water content of 40 to 45% by weight and a solids content of 55 to 60% by weight is prepared by digesting cellulose fibers in an amount of from 2 to 12% by weight of the solids content with water and mixing them with fillers and with a binder comprising cement and/or lime hydrate and substances containing reactive calcium silicates to form a thick pasty mixture, whereupon the thick pasty mixture is introduced in a predetermined amount into the frame of a bottom mold of a single-shot press which further includes a top mold. The mixture is essentially leveled out, formed by closing top and bottom mold, and, via dewatering fabrics and channels in the top and bottom molds, dewatered. Finally, the mixture is compacted and vented, whereupon the raw board is demolded and autoclaved.