Highly insulated and unventilated flat roofs in timber construction were more frequently applied in the last years. According to German standard DIN 4108-3 an internal tight vapour barrier is required for a verified construction, but also can easily cause moisture damages. At same time new building products, airtight construction, dry timber and wood based panels give new opportunities for safe and durable constructions. By long term laboratory examinations, numerical simulations and in-situ measurements for German climate conditions, design principles and recommendations which guarantee a durable use of wooden flat roof constructions in combination with high energetic efficiency, including ecological building products and without chemical treated timber according use class 0 of DIN 68800 were developed.     «

Highly insulated and unventilated flat roofs in timber construction were more frequently applied in the last years. According to German standard DIN 4108-3 an internal tight vapour barrier is required for a verified construction, but also can easily cause moisture damages. At same time new building products, airtight construction, dry timber and wood based panels give new opportunities for safe and durable constructions. By long term laboratory examinations, numerical simulations and in-situ...     »