Results of experimental and theoretical investigations of the coating of an industrial building, in which the ribbed plates are rigidly connected between themselves and the girder in the places of their bearing by welding the protruding bars of the steel reinforcement and monolithic concrete have been presented. Compatibility of the work of structures and the influence of such connection on the work of the girder and ribbed plates have been estimated. Vertical plate displacement as per the lines of longitudinal ribs has been determined. Theoretical definition has been made by means of the LIRA software package and the program developed at VlSU. In the first case, the solution has been obtained by step-by step iterative method using the exponential law of concrete deformation and a bilinear diagram of the state of the reinforcement. In the second case, the method of elastic solutions has been used, where the method of finite differences has been used for each iteration. The recommended norms trilinear deformation diagram has been adopted for the compressed concrete, and bilinear deformation diagram has been adopted for the reinforcement. Comparison and analysis of the results have also been presented.