The invention relates to a construction apparatus comprising a base carrier, a mast which is arranged on the base carrier in a pivotable manner, a first hydraulic cylinder and a second hydraulic cylinder for erecting the mast, which are connected to each other in an articulated manner in a connecting section, the first hydraulic cylinder being linked to the base carrier and the second hydraulic cylinder being linked to the mast, and a coupling rocker-arm which is linked on one side to the mast and on another side to the connecting section. According to the invention in the part of the connecting section a spacer is arranged, through which the connecting section is supported on the mast in a detachable manner.