CFD simulation models of various sizes of openings in attics are simulated to assess the effect of openings on uplift pressure on different roofs types. The types of roofs and opening parameters in attics are analysed based on the CFD simulations using ANSYS Fluent software. The roofing materials, roof-to wall connections and support strings are analysed based on reports and field observations data. Roof damage is assessed based on the roofing materials, roof-to wall connections, support strings, types of roofs and opening parameters in attics. In this study, damage from the 2011 windstorm to traditional roofs in seventeen districts in Bhutan is assessed by using damage reports, field observations and computational fluid dynamic (CFD) simulations. The impact of the ‘secondary roof’ effects is noticeable for small modules compared to larger modules.

This is most likely attributed to the effect of a raised ‘secondary roof’ formed over the main roof. Solar panels mounted in zone 1 are locally subjected to higher suction at their outer edges. Avoiding the roof critical zones (zone 3 and zone 2) is recommended to avoid high net minimum pressures acting on the solar panel modules. Nevertheless, the cladding loads on individual modules may be lower or higher than those on the corresponding area of a bare roof (depending on their location, array configuration and roofs slope). The comparison shows a good agreement with the ASCE 7-2010 standard provisions for the main force resisting system. The results from the wind-tunnel investigation are compared with ASCE provisions for residential bare roofs. Wind loads on the solar panels mounted on several zones of the roofs were systematically investigated in a boundary-layer wind tunnel for different wind directions. This paper presents wind load investigations on solar panel modules mounted on low-rise buildings with gable roofs that have two distinct slopes.

Asce 7 2010 free pdf