fiber reinforcing material not of metal for building purposes in the form of [individual fibers, ] mat, fabrics and [ rovings,] applied to building structures, brick, stone and concrete, for the purposes of repair and reinforcing; reinforcing materials not of metal for building purposes, namely, pre-formed, fiber-reinforced sheets, panels, and plates for use in reinforcing of building structures, brick, stone and cement, and consisting of fiber reinforcing impregnated with a hardened resin