The Influence of Climate Change and Interior Insulation on Salt Damage in Masonry Facades

Salt-induced deterioration is a prominent concern when assessing the degradation risk associated with masonry facades. While there exists a substantial amount of knowledge about the mechanics of salt behaviour, quantitative assessment of this risk remains a challenge. Previous literature predominantly focuses on the evaluation of single salts; however in reality, masonry walls often feature a mixture of different salt types. Salt damage occurs as a consequence of recurrent crystallization-dissolution cycles, exerting substantial pressure on the pore surfaces of stones. Relative humidity is a fundamental driving factor for the amount and behaviour of the crystallization-dissolution cycles. This paper combines the findings derived from research on the kinetics of typical salt mixtures present in heritage buildings in Belgium with the outcomes of hygrothermal simulations. Heath-,Air- and Moisture (HAM) modelling provide relevant insights into the interaction between climate change, interior insulation, salt damage, and the hygrothermal characteristics of masonry constructions. The primary objective is to investigate the impact of climate change and interior insulation on salt damage, as both factors have the capacity to drastically change the hygrothermal behaviour of masonry walls. The results of this investigation underscore the significant influence of climate change and interior insulation on salt behaviour within masonry facades. The paper highlights the risks inherent in preserving historical masonry structures when subjected to retrofits or changing climatic conditions. It proves the necessity for adaptive preservation strategies in response to challenges faced for the preservation of our built heritage.