EN ISO 13788 : Hygrothermal performance of building components and building elements - Internal surface temperature to avoid critical surface humidity and interstitial condensation - Calculation methods (ISO 13788:2012).

This document presents simplified calculation methods for assessing the minimum internal surface temperature required to limit the growth of mould and other surface-condensation problems, based on indoor temperature and relative humidity. It also makes it possible to estimate the risk of interstitial condensation caused by water-vapour diffusion, without taking into account several important phenomena: variations in material properties according to their moisture content, capillary absorption and liquid-moisture transfer, the air permeability of building elements through gaps or air cavities, and the hygroscopic capacity of materials. Finally, it addresses the drying time of water present in a layer between two layers with high vapour resistance, as well as the risk of internal condensation during this drying process.