Hydrophobing polymer powder that can be redispersed in water

The invention relates to a hydrophobing polymer powder that can be redispersed in water, containing: a) a polymer comprising, a1) between 50 and 90 parts per weight vinyl acetate monomer units, a2) between 5 and 50 parts per weight vinyl ester monomer units of vinyl esters of alpha-branched monocarboxylic acids comprising between 2 and 20 C atoms, a3) between 1 and 30 parts per weight (meth)acrylic acid ester monomer units of alcohols comprising between 1 and 15 C atoms, a4) between 0 and 40 parts per weight vinyl ester monomer units of long-chained monocarboxylic acids comprising between 10 and 20 C atoms, a5) between 0 and 20 parts per weight ethylene units and optionally a6) additional auxiliary monomer units, whereby the amounts in parts per weight total 100 parts per weight; b) between 0.5 and 30 wt. % of one of more water-soluble protective colloids; c) between 0 and 20 wt. % of an organosilicon compound; d) between 0 and 20 wt. % of a fatty acid or derivatives of fatty acids; and e) between 0 and 30 wt. % of an anti-blocking agent, whereby the amounts in wt. % are relative to the total weight of the polymer a).