Re-strengthens and refurbishes failed cement/sand screeds to a better than new condition with the minimum of down time and disruption to the occupants in heavy use areas such as hospital corridors, operating theatres and commercial buildings. An ultra low viscosity, solvent free liquid for restrengthening and restoration of failed cement/sand screeds. PHS penetrates into the defective screed, filling voids and binding loose particles together to provide a high strength material.