The experimental study was carried out in two stages: Stage one constituted a test of the mechanical strength and moisture resistance of hemi-hydrate gypsum (CaSO4. \H2O) combined separately with acrylic, epoxy and silicone resins. With the objective of determining the best-performing mixture, different types of acrylic, silicon and epoxy-based polymers in varying quantities were combined with gypsum. Succeeding the capillary trials of the gypsum specimens, the specimens were subjected to submersion in water for 7 and then 15 days. The specimens were then weighed to establish the relative amount of moisture adsorption. Measurement of the mechanical strength of the specimens was conducted by compressive- and flexural tests.