Abstract: Fiber containing plaster boards are prepared by superimposing a plurality of board blanks one on top of the other such that the direction of the fiber orientation in the superimposed blanks deviates one from the other. The board blanks are formed in a conventional manner from a suspension of calcium sulfate capable of setting, reinforcing fibers and a quantity of water beyond the quantity of water necessary for setting the calcium sulfate capable of setting. After mechanically removing excess water from the suspension to form the board blanks, two or more of these blanks are placed one on top of the other and are connected under pressure and dried. Thereafter, a predetermined number of board blanks having a direction of the fiber orientation deviating one from the other, are placed one on top of the other and are pressed together prior to or during the setting of the calcium sulfate.