Glass fiber as reinforcement for portland cement paste has been looked on as an interesting but exotic possibility. Combined with cement, it offers high impact resistance, increased tensile and bending strength and an overall decrease in weight. Until recently, however, there has been no glass fiber sufficiently resistant to alkali attack by hydrated portland cement to make it a practical building material. Such an alkali-resistant glass has been developed in England by the Building Research Establishment and Pikington Brothers Limited. After five years of joint development by the two organizations, glass fiber reinforced cement (GRC) is now emerging as a new and versatile material for the construction industry. The alkali resistant glass fiber can be supplied as continuous strand, chopped strand, crenette, wool ropes or woven fabric. Normally it is supplied as continuous or chopped strand and the GRC composites are produced by one of three standard fabrication techniques followed by a curing period. The premix process requires mixing in much the same way as perlite, vermiculite or expanded polystyrene concrete; chopped fiber is introduced into a cement slurry in a pan or paddle mixer. The mixture is cast with vibration. In the presence of a small quantity of suitable lubricating admixture, such as polyethylene oxide or methyl cellulose, it has been possible to introduce five to six percent by volume of 25 millimeter long fibers into the cement mix. This premixed material can be cast, sprayed, injection molded or extruded. In the direct spray technique, chopped fibers 38 millimeters long and cement slurry are deposited simultaneously from a hand-held gun into a mold. This method is particularly suitable for such application as architectural cladding panels. The automatic spray method is similar except that a fiber and cement slurry gun traverses the mold automatically as the mold passes beneath it. A water-cement ratio of .5 is used and the excess water is removed by suction from the underside of the sheet after fabrication. While the cement is still uncured, the material can easily be formed onto a two dimensional mold.