A wall bead 10 comprising a central longitudinally extending portion 13, a first elongate flange 11, and second elongate flange 12 which extend longitudinally of the bead, and which separately comprise a front and rear surface. The wall bead 10 further comprises a plurality of teeth 16 disposed upon the first and second flange at longitudinal positions thereon, wherein the teeth are directed away from the respective flange, substantially forwardly of the respective flange, along a common direction that is along the wall bead.