New open-web roofs for integrating heat preservation & insulation and structural functions

The thermal performance of building envelope is a major requirement for generating a comfortable and hygienic interior environment. A roof is a main part of building envelope and provides protection from thermal damage caused by the excessive hot sunshine. In order to improve this thermal roof performance, the use of the air gap in the roof can be considered. This study presents a new type of open-web roofs, which integrates the structural functions and thermal behaviours for building roofs, in particular large span roofs. The conceptual analyses for the proposed open-web roofs on both mechanical properties and thermal performances are carried out. The comparison of material usages and thermal performance between the open-web roof and traditional roof structures is presented for a successfully constructed building. The results from the real case study show the advantages of the new open-web roofs over traditional roofs.