Impact of insulating glass unit seal failure on its deflections and user safety

<ns3:p>The article discusses the impact of seal failure in insulating glass unit (IGUs) and the resulting loss of filling gas on deflections as well as the operational safety of glass structures, with particular emphasis on roof glazing and skylights. The main objective was to demonstrate the critical role of the gas in ensuring composite action between the glass panes when transferring external loads. Numerical analyses were performed in the RF-Glass module of the RFEM 5 software for typical insulating glass configurations. The behavior of the glazing unit in a fully sealed state was compared with the situation after seal failure and gas loss, where the external load is borne solely by the outer pane. Additional comparisons of various structural variants (different thicknesses, tempering, lamination of inner and outer panes, as well as single-chamber and double-chamber arrangements) made it possible to assess how modifications to the glazing composition affect stiffness and stress levels. The results highlight that gas loss significantly worsens the working conditions of the outer pane and may lead to exceeding the ultimate limit state of load-bearing capacity. In extreme cases, this can result in sudden failure of the element and pose a risk to user safety. The article emphasizes the need for special care regarding the airtightness of insulating glass units and the rational selection of layer configurations in the design of modern metal-glass structures.</ns3:p>