mill the multi stage polymer in an amount of 0 005 0 10 by weight based on the weight of the cement and more preferably about 0 015 0 10 by weight cement and the air entraining agent preferably in an amount of 0 001 0 02 based on the weight of the cement preferably the addition is achieved using a one time introduction of the multi stage polymer and air entraining agent which are pre mixed together as an emulsion the emulsion can comprise 20 80 water further exemplary mortar additives of the invention optionally comprise in addition to the multi stage polymer and air entraining agent a set retarder 0 35 by total weight and a superplasticizer water soluble set retarding agents for portland cement are well known and are preferred for use in the present invention if the additive is provided in the form of an emulsion then the set retarding component of the additive should not be such that it destabilizes the emulsion or causes the additive to be overly viscuous water soluble set retarding agents useful in the present invention include carbohydrates such as monosaccharides for example glucose and fructose disaccharides for example raffinose polysaccharides for example starch and cellulose as well as derivaties thereof such as pregelatinized starch dextrin corn syrup and carboxymethylcellulose polyhydroxy polycarboxylic compounds such as tartaric acid and mucic acid lignosulfonic acid and salts thereof such as calcium magnesium ammonium and sodium lignosulfonate water soluble salts of boric acid such as the alkali metal salts thereof zinc oxide and water soluble silicone compounds as well.