Abstract
Hemp wools are environmentally friendly materials that are used for thermal insulation of building. These fibrous materials are the places of moisture transfer and storage that impact on thermal performances of the material. In this work, two kinds of hemp wool are studied: hemp wool with an organic binder (called HW1) and hemp-cotton wool with a polyester binder (called HW2). The investigations are based on water vapor sorption and on water vapor permeability measurements. The two kinds of hemp wool show similar sorption isotherm with quite high values of water content. The water vapor permeability is quite high too.