A wall anchor for use in an insulated cavity wall has an elongated body extending from a driven end to a driving end. The driven end is adapted to be mounted on an inner wythe of a cavity wall structure. A rotation control portion of the elongated body may include teeth formed on the surface. A collar with at least one aperture for a veneer tie is located near the driving end. The collar may have a pawl associated with it and positioned to engage the teeth on the elongated body. The teeth of the elongated body and the pawl of the collar form a ratchet structure. The collar can be rotated relative to the wall anchor only in a single direction, with the interengaging ratchet structure preventing rotation in the opposite direction.