Risk Assesment of Water Vapor Condensation In Wall Made of Hemp-Lime Composite

The paper presents issues associated with moisture presence in the wall partitions. As the wall material a lime-hemp composite was selected. Materials containing organic components are sensitive to excessive amount of moisture. One of the most important sources of moisture in the walls is diffusive water vapor, which may condense inside the partition. An important parameter of wall material is water vapor permeability. Inappropriate indor air relative humidity and the temperature of the wall surface can contribute to the growth of mold. In turn, the accumulated condensate inside the barrier, may worsen the thermal insulation parameters and reduce the durability of the material. For the analysis there were selected two external wall constructions manufactured of the hemp-lime composite in two versions, one insulated from the inside and the second one from the outside with wool hemp. Both variants are finished with plaster or wood cladding. To avoid critical surface humidity, internal surface temperature was calculated and the possibility of interstitial condensation in the analyzed walls was determined. Calculations were made assuming the specified conditions in a monthly cycle for Lublin (Poland) location according to PN-EN 13788 standard.