The recommended option for rehabilitation of operated combined insulated rolled roofs allows to reduce the cost of measures to ensure safe working conditions. The article proposes a construction solution similar to an inverted roof. In the proposed solution, the role of a vapor barrier is played by the repaired layers of the existing waterproofing layer to which the insulation board has been attached.

Combined insulated rolled roofs, all layers of which are sequentially laid on the supporting structure and covered with a waterproof carpet, make up more than 80 % of the roofs of residential and public buildings in operation and under construction. Such a significant number of structures with a combined roll roofing in the Republic of Belarus is due to the fact that in the early 70s of the last century, a program for the development of prefabricated housing was launched in the Soviet Union. As practice has shown, after three to five years of operation, the combined insulated roll roofs needed current repairs – to eliminate leaks. The repair basically boiled down to the gluing of additional layers of rolled waterproofing material in the areas of roof leaks. Field studies have allowed us to establish the reasons why, in less than 10–12 years of operation, the combined insulated rolled roofs need major repairs. The analysis of the results of field studies has shown that the main factor affecting the failure of the roof is the high humidity of the insulation material. The main reason for moistening the material of the thermal insulation layer during the operation of the roof is the destruction of the vapor barrier layer. Based on the results of the performed field studies and regulatory documents of the Republic of Belarus, the authors of the publication offer a constructive solution and technology of work for the rehabilitation of operated combined insulated rolled roofs. The mainadvantages of the proposed solution are: provision of any thermal resistance to heat transfer of the combined coating without dismantling the structural elements of the existing roof; use of PVC membranes as a water-insulating carpet, which will allow to eliminate roof leaks within 20 years of operation without additional costs.

Introduction. Resistance to heat transfer is considered the main criterion of energy operational efficiency in the design of enclosing structures of buildings and structures. Therefore, the calculation of the values of the normalized resistance to heat transfer, for each locality of the Republic of Belarus, taking into account the actual outdoor temperatures and the duration of the heating season is an urgent task. Materials and methods. To assess the energy efficiency of enclosing structures, the value of annual heat losses Q, kWh/m2, through 1 m2 of the structure was adopted. The calculation of the values of the normalized heat transfer resistance for each locality of the Republic of Belarus, taking into account the actual outdoor air temperatures and the duration of the heating season, was carried out according to the method recommended by V.G. Gagarin. A comparative analysis of the results obtained according to the methods recommended by TCP 45-2.04-196-2010* and SP 50.13330.2012 is carried out. Results. The calculations determine the values of the normalized heat transfer resistance for each locality of the Republic of Belarus, taking into account the actual outdoor air temperatures during the heating period and the duration of the heating season. To facilitate the design of insulated walls, a map of the recommended (calculated) values of the heat transfer resistance of the external walls of residential buildings for the territory of the Republic of Belarus is constructed. Conclusions. According to the results of the performed studies, it was found that the economic efficiency in the design of insulated walls according to the method recommended by TCP 45-2.04-196-2010*, depending on the region of the Republic of Belarus for which the design is being carried out, is on average from 6 to 8 BYN per 1 m2 of insulated wall.