The study of the effect of thickener and retarder on the technological properties of the GPM START. Full-factor plans for a two-factor model have been developed, with a minimum (0.1%; 0.005%) and maximum (0.2%; 0.05%) dosage level of pore-forming and water-holding additives, respectively. The regression equations of the output parameters obtained in the form of a polynomial of the second-degree using regression and correlation analysis of experimental data. An analysis of the values of the partial correlation coefficients showed that the start of setting and expansion determined mainly by the moderator. With an increase in the dose of water-holding and pore-forming additives from 0.1% to 0.2% and from 0.005% to 0.05% of a binder, respectively, for all possible combinations of the dosage of thickener and setting retarder, an increase in setting time is observed by 10 ... 72%, and expansion by 33 ... 80%. The mixture in which the amount of thickener was 0.2% (at the upper level) and the amount of moderator was 0.04% (at the lower level) turned out to be the least sensitive to the increase in water-holding and pore-forming additives. © 2023 Author(s).