According to statistical data of error of design of building constructions are one of the main reasons for accidents of buildings and constructions of different function. In article results of inspection and testing calculations of load-carrying structures of covering of industrial building are considered. It is established that the mistakes made at design and mounting of metal roof frames of the building have led to change of their constructive scheme and redistribution of efforts in rods. Mass loss of stability the overloaded compressed elements has turned out to be consequence of it. The analysis of similar situations allows to avoid their repetition, not to allow emergence of emergencies and unjustified increase in material and financial expenses in use of objects.

Keywords: design errors, defect of mounting, constructive scheme, overload, metal frаme work