PVA fibres are the new alternative to glass reinforcements for cement systems. They are a synthetic polyvinylalcohol fibre with chemical and physical attributes that make them particularly suitable to the Jesmonite family of Polymer Modified Cement materials. They have high strength combined with low elongation and high modulus. They provide advanced adhesion to the polymer cement matrix as well as inherent resistance to the degrading effects of the alkalinity of such a matrix. We strongly recommend their addition to Jesmonite systems when high strength retention after severe exposure make them especially suitable to resist frost damage in the most harsh external environments.