An open grid fabric for reinforcing wall systems and a method of making same. First and second sets of substantially parallel, selected rovings are combined using certain knits, leno weaves, or adhesive methods. The rovings are direct-sized with at least a silane sizing and preferably have a linear density between 100 and 2000 grams per thousand meters and are arranged at an average of 3 to 10 ends per inch. A polymeric coating is applied to the fabric at a level of 10 to 150 parts dry weight of resin to 100 parts by weight of the fabric while assuring that the open grid remains open. A method for reinforcing a wall system and a wall segment product utilizing the novel open grid fabric of the present invention are also disclosed.