A method for joining surfaces, the method comprising the steps of: - providing a first surface and a second surface; - at least partially applying a hot-sealable coating system, comprising: a polyurethane and/or polyurethane-polyurea polymer which is obtainable by the reaction of: at least one diol and/or polyol component, at least one di- and/or polyisocyanate component, at least one component having sulphonate and/or carboxylate groups, optionally mono-, di- and/or tri-amino-functional and/or hydroxyamino-functional compounds, optionally other isocyanate-reactive compounds; and an olefin vinyl acetate copolymer, wherein the polyurethane and/or polyurethane-polyurea polymer has a glass transition temperature of ≤ 10° C; the glass transition temperature being determined by differential scanning calorimetry according to DIN 65467 at a heating rate of 20 K/min; and wherein the olefin vinyl acetate copolymer has a minimum film forming temperature (white point temperature) of> 40° C; the minimum film forming temperature being determined by differential scanning calorimetry according to DIN ISO 2115 (white point temperature) at a heating rate of 20 K/min; to the first and/or second surface; - contacting the first surface with the second surface so that the applied hot-sealable coating system is located between the first and the second surface to give a layered assembly; - heating the layered assembly to a temperature of ≥ 50° C and simultaneously applying a pressure of ≥ 1 bar to the layered assembly. - providing a first surface and a second surface; - at least partially applying a hot-sealable coating system, comprising: a polyurethane and/or polyurethane-polyurea polymer which is obtainable by the reaction of: at least one diol and/or polyol component, at least one di- and/or polyisocyanate component, at least one component having sulphonate and/or carboxylate groups, optionally mono-, di- and/or tri-amino-functional and/or hydroxyamino-functional compounds, optionally other isocyanate-reactive compounds; and an olefin vinyl acetate copolymer, wherein the polyurethane and/or polyurethane-polyurea polymer has a glass transition temperature of ≤ 10° C; the glass transition temperature being determined by differential scanning calorimetry according to DIN 65467 at a heating rate of 20 K/min; and wherein the olefin vinyl acetate copolymer has a minimum film forming temperature (white point temperature) of> 40° C; the minimum film forming temperature being determined by differential scanning calorimetry according to DIN ISO 2115 (white point temperature) at a heating rate of 20 K/min; to the first and/or second surface; a polyurethane and/or polyurethane-polyurea polymer which is obtainable by the reaction of: at least one diol and/or polyol component, at least one di- and/or polyisocyanate component, at least one component having sulphonate and/or carboxylate groups, optionally mono-, di- and/or tri-amino-functional and/or hydroxyamino-functional compounds, optionally other isocyanate-reactive compounds; and at least one diol and/or polyol component, at least one di- and/or polyisocyanate component, at least one component having sulphonate and/or carboxylate groups, optionally mono-, di- and/or tri-amino-functional and/or hydroxyamino-functional compounds, optionally other isocyanate-reactive compounds; an olefin vinyl acetate copolymer, - contacting the first surface with the second surface so that the applied hot-sealable coating system is located between the first and the second surface to give a layered assembly; - heating the layered assembly to a temperature of ≥ 50° C and simultaneously applying a pressure of ≥ 1 bar to the layered assembly.