Gypcrete Surface Preparation:  

All wood subfloors must be structurally sound, thoroughly clean (use vacuum or broom), dry, and free from mud, wax, grease, oil and other contaminants and fill cracks with a crack filler. Gypcrete will not correct or compensate for a structurally defective substrate. If there is any movement in your wood floor that may cause concern about bonding of the Gypcrete to the subfloor material, staple 2.5 pound metal lath to floor as reinforcement prior to pouring Gypcrete.