The technical hemp as fast-growing plant belonging to rapidly renewable sources has prospect not only in terms of biomass energy recovery, but also of material in building application in accordance with the principles of sustainable development. Recently, hemp based composites have attracted attention due to their environmentally friendly properties. Because of the main disadvantage of natural plant fibres reinforced composites consisting in high moisture absorption ability of organic filler, chemical treatments of fibres are applied. Moisture in humid atmosphere and water immersion of biocomposites lead to the degradation of fibre-matrix interface as well as mechanical properties. In this paper, the study of long-term water storage of hemp hurds composites at room temperature was made. Water absorption of composites based on unmodified and chemically modified hemp hurds in dependence on water storage duration was monitored and kinetic curves were described by model. Based on evaluation of sorption curves using model for composites based on natural fibres, diffusion of water molecules in composite is anomalous in terms of the Fickian behaviour.
