Insulating coat to prevent mold growth in thermal bridges

Abstract

Mold growth in buildings represents a widespread issue. It is, indeed, not only an aesthetic problem, but above all, a serious concern for the indoor air quality, which is directly related to the occupants’ health.Most of the existing residential buildings are poorly insulated and heavily affected by the presence of thermal bridges, that constitute the first area colonized by mold.In this paper the mitigation of the thermal bridges impact by applying a fine layer of insulating rendering coat in the interior side was analyzed. The numerical analyses were focused on a typical thermal bridge occurring on the Italian building stock between a vertical wall and a concrete slab and were carried out through dynamic 2D Heat and Moisture Transfer simulations. Moreover, the results related to the surface temperatures and relative humidity were used for the calculation of the mold index by means of the VTT growth model.Results are encouraging showing that the presence of the fine insulation rendering coat could moderately reduce the effect of the thermal bridges but can have a significant effect on the mold growth risk reduction.