Water-redispersible dispersion powder composition obtainable by drying an aqueous dispersion composition based on at least two different water-insoluble emulsion polymers, and optionally further additives, for ultraflexible, water-tight, hydraulically setting systems, characterized in that a) an emulsion polymer A has a glass transition temperature T g of 10°C to 80°C and an emulsion polymer B has a glass transition temperature T g of -60°C to +20°C, with the glass transition temperature T g being determined as midpoint temperature according to ASTM D3418-82, and the difference between the glass transition temperatures T g of emulsion polymers A and B being at least 5°C, with the ratio of the solids content of emulsion polymer A to the solids content of emulsion polymer B being 95: 5 to 5: 95, b) the emulsion polymers A and B each contain 0 to 70 mol% vinyl acetate monomer units, based on the respective total monomer content of the individual emulsion polymers, and emulsion polymers A and B are each obtained by means of emulsion polymerization, microemulsion polymerization or inverse emulsion polymerization, c) the glass transition temperatures T g and the weight ratios of emulsion polymers A and B are set such that the lowest film-forming temperature according to DIN 53787 of the 50% aqueous dispersion composition is 15°C or less, d) the monomers, stabilizing systems of emulsion polymers A and B, and optionally the further additives of the dispersion composition are selected such that the cement compatibility is guaranteed, with the cement compatibility being determined through the ratio of the time which a mixture of 10 g cement and 1.0 g dispersion powder composition in 190 g water needs to form a transparent water phase of 25% of the total volume of water, cement and dispersion powder composition in a measuring cylinder, to the corresponding time of the same cement/water mixture without dispersion powder composition, with the ratio being 0.3: 1 or higher, and wherein the stabilizing systems of emulsion polymers A and B are selected from one or more protective colloids; and e) optionally further additives are added before, during and/or after the drying. a) an emulsion polymer A has a glass transition temperature T g of 10°C to 80°C and an emulsion polymer B has a glass transition temperature T g of -60°C to +20°C, with the glass transition temperature T g being determined as midpoint temperature according to ASTM D3418-82, and the difference between the glass transition temperatures T g of emulsion polymers A and B being at least 5°C, with the ratio of the solids content of emulsion polymer A to the solids content of emulsion polymer B being 95: 5 to 5: 95, b) the emulsion polymers A and B each contain 0 to 70 mol% vinyl acetate monomer units, based on the respective total monomer content of the individual emulsion polymers, and emulsion polymers A and B are each obtained by means of emulsion polymerization, microemulsion polymerization or inverse emulsion polymerization, c) the glass transition temperatures T g and the weight ratios of emulsion polymers A and B are set such that the lowest film-forming temperature according to DIN 53787 of the 50% aqueous dispersion composition is 15°C or less, d) the monomers, stabilizing systems of emulsion polymers A and B, and optionally the further additives of the dispersion composition are selected such that the cement compatibility is guaranteed, with the cement compatibility being determined through the ratio of the time which a mixture of 10 g cement and 1.0 g dispersion powder composition in 190 g water needs to form a transparent water phase of 25% of the total volume of water, cement and dispersion powder composition in a measuring cylinder, to the corresponding time of the same cement/water mixture without dispersion powder composition, with the ratio being 0.3: 1 or higher, and wherein the stabilizing systems of emulsion polymers A and B are selected from one or more protective colloids; and e) optionally further additives are added before, during and/or after the drying.