Abstract

External wall failures caused by rainwater ingress are very common in Turkey. External wall systems that fail to meet the expected watertightness performance may cause premature deterioration of building components, create health hazards for users, and lead to a financial burden for building owners and in respect to the premature deterioration of public buildings, this also has repercussions on the national economy. In addition to the current climatic conditions, thermal and moisture loads that effect the buildings are expected to increase in the future due to climate change. In regards to climate change mitigation strategies, as have been emphasized for the building sector in Turkey, the national government is promoting the use of thermal insulation. However, given that the thermal performance of the most commonly used thermal insulation materials in Turkey are affected by moisture, it is important to evaluate the hygrothermal performance of external wall systems to help ensure the effectiveness and longevity of any proposed measures to mitigate the effects of climate change on building performance. In this paper, the state of the art is presented in respect to investigations of the hygrothermal performance of external wall systems. The research is analyzed based on climatic conditions to which the wall is exposed, the type of external wall assembly investigated, and the method of investigation described in the studies reviewed. The results indicate that the hygrothermal performance of external walls has been extensively investigated; however, there is relatively little research focusing on the hygrothermal performance of external walls subjected to the current climatic conditions of Turkey. In those studies that focused on evaluating the hygrothermal performance of external wall systems under future climate projections, these have been conducted for the cold climate regions of Canada, USA, Norway, and Finland. The hygrothermal performance of external walls under future climate projections for any region of Turkey has not yet been explored.