A butt joint connector is described which includes a plurality of ribs (31, 50) which are interconnected by batons (32) or webs (52). The ribs (31, 50) define first and second arms (31a, 31b and 50a, 50b) which form attachment surfaces which are inclined with respect to one another so that when connected to butt joint edges of plasterboard, the region adjacent the butt joint edges is pulled towards the connector so as to form a recess which is filled by a filler material to finish the butt joint.