A steel beam with perforated steel web is a type of flexural members, which is characterized by the decreased materials consumption. Existence of holes in the web enables to simplify placement of communications on the other hand. The using of beams with perforated web with hot-rolled double-T cross-section as a girder of transversal frame of trees hothouse is analysed in the paper. The beams are considered under the action of design vertical load, consisting from dead weight of the roof and snow load. The value of design vertical load is equal to 28kN/m. The grade of steel was S235. The dependence between diameters of holes, distances between holes, height of the beams cross-sections and materials consumption was obtained on the basis of numerical experiment. The numerical experiment was conducted for the simple beam with the span equal to 12 m. The obtained dependence allows determining rational from the point of view of materials consumption diameters of holes, distances between holes and height of the beam, which were equal to 0.25 m, 1.03 m and 0.55m, correspondingly. The methodology for determination of coefficients of stress concentration was considered in the paper. The stress concentration factors were obtained by the FEM with the using of computer program ANSYS v14, the obtained results were also compared. It was stated that the difference does not exceed 2.34%.