Abstract: A method for treating a textile material web for reducing a gas-permeability of the textile material web. The method includes providing the textile material web with a first side having a planar configuration and a second side having a planar configuration, the first side being opposite to the second side, transporting the textile material web in an advancing direction, and reducing the gas permeability of the textile material web. The gas permeability of the textile material web is reduced by applying water to the first side and/or the second side of the textile material web, guiding the textile web material through a first treatment gap which is formed by a first treatment roller and a first counter tool, and in the first treatment gap, pressure treating the textile material web and thermally treating the first side and/or the second side of the textile material web.