PurposeThis paper aims to investigate the comfort properties of modern functional clothing, such as moisture and heat transport. Transport properties are evaluated for real barrier membrane clothes for sport application, under real weather conditions in Middle Europe.Design/methodology/approachThe different combination of functional clothing, with barrier membrane, were investigated under different temperatures and relative moistures inside and outside clothing layers. Water vapour permeability was measured under the steady‐state conditions, by sweating guarded‐hotplate test.FindingsThis paper describes the theoretical analysis of moisture transport, and its influence on thermal conductivity; the paper investigates various barrier fabrics for sport apparel, and their ranges of water vapour transport ability under real weather conditions.Research limitations/implicationsAll received results are based on the transport of water vapour through a semi‐permeable membrane and are supposed to be conducted mainly within a process of diffusion.Originality/valueThis paper is focused on the theoretical analysis of transport by diffusion of water vapour through porous semi‐permeable barrier textile material, and evaluates the real possibilities for sport applications. The level of transport is limited and mainly depends on the difference of the partial pressures of water vapours outside and inside the porous clothing material.