Airtightness in the steel lightweight construction - building envelopes in sandwich construction

The airtightness of buildings gains in importance ever more for the planning ofbuildings. The regulations for the securing of the energy-saving thermal protectiondemand beyond that a durably air-impermeable building envelope, in order to avoidunnecessary thermal losses and building damages. This has effects on the designand construction of roof and facade systems in metal lightweight construction.Against this background the aspect of airtightness is to be treated with increasedattention when planning and design of steel sandwich constructions for roof andfacade systems.As realised examples [10] show, a high extent of airtightness is attainable withbuildings in metal lightweight construction when careful planning and designing isdone.In the context of several national and European research projects in particular thecharacteristics of construction physics are examined with numeric and experimentalmethods with buildings and components in metal lightweight construction at the chairof steel and light metal construction of the RWTH Aachen in close co-operation withthe Industrieverband fr Bausysteme im Metallleichtbau (industry association forbuilding systems in the metal lightweight construction).For this purpose component test plants were arranged, with which for exampleextensive research into joints of sandwich constructions are accomplished.With the help of the existing measuring technique (e.g. infrared camera, BlowerDoor,heat flow measuring plates, radiation and flow measuring instruments, etc.) on siteinspections can be made concerning the quality of the building envelope. At thesandwich-demonstration-house among other things the thermal characteristics of thebuilding envelope are examined as well as new constructions for the improvement ofthe heat accumulation, the summer thermic protection and the airtightness are tested.