Conditions for the formation of ice dams on pitched roofs of buildings with cold attics

Introduction. The article describes the mechanism of ice formation on the roofs of buildings with pitched roofs and cold attics. Materials and methods. The authors developed a model and a heat balance equation for an unheated attic room and proposed a set of measures to normalize the temperature and humidity modes in unheated attics. Results. The study demonstrates dependences between the air temperature in the attic and the outdoor air temperature before and after the implementation of the proposed set of measures designated to normalize the temperature and humidity modes. The findings suggest that after the insulation of (1) enclosing structures separating a cold attic from heated rooms, (2) the walls of ventilation ducts, crossing the attic space and (3) the pipelines of the down-feed heating system, the outdoor temperature range is significantly reduced, which reduces the likelihood of roof icing. Conclusions. In addition, the implementation of the proposed set of engineering and technological measures allows not only increasing the thermal insulation of enclosing structures and pipelines of a heating system, but also reduces thermal energy losses in transmission and the consumption of thermal energy in a building during a cold season, improves the indoor climate parameters on the upper floors of a building, reduces the risks of damage to the roofing during mechanical snow removal, thereby increasing the maintenance period of structural and enclosing elements of the roof.