Horizontal and vertical constructions which have changed during civil engineering development are fundamentals of structural supporting system. Materials used in constructions according to modern trends and meeting the requirements of statics have changed according to the requirements of structures. Over time, the need for ecological buildings and sustainability has become more important. Following the cooperation in the area of material development and design of structures new trends were applied and thin walled beams based on wood were developed. Beam construction changed due to increasing demands on heat transmission and price. Nowadays, they meet the highest standards and at the same time, they are used to support the structure during the building lifecycle. As the material changed, the structural design procedures have to be changed as well. Construction properties as well as processes and situations associated with them have to be analysed according to the standard. In order to unify all procedures, the European standard Eurocode was created. Processes associated with structural design, material classification as well as load effects are given there. Immediate load carrying capacity of modern thin walled beams and load effects in time can be evaluated using the method of partial coefficients. At the present time, thin walled beams are more often used for supporting systems forasmuch the building properties associated with statics and heat transmission are at very high level. In foreign countries, they are often used for larger construction projects with statics problems where areas of embedded steel beams can be found. Therefore, the cross section has to be changed at point of embedding. Most of producers do not allow making any changes in the table of beam and only specific holes in the wall are accepted. Maximum bending moment that is minimal at the point of application is caused by load in the beam. Shear tension that the beam has to resist at the point of weakening is still the problem. The thesis is focused on the proposal to strengthen the beam and the testing method maximising shear effects at the point of weakening. Following the analysis of measured values gained on various beams and their evaluation I propose solutions for practice and further analysis.