In a first aspect there is disclosed a reinforcing spacer (10) for use in constructing a concrete slab. The spacer (10) includes a first reinforcing arm (12) having a first arm base (16), a first arm wall (18) and a first arm support surface (20) provided on the first arm wall (18). The spacer (10) further includes a second reinforcing arm (14), transverse to the first reinforcing arm (12). The second reinforcing arm (14) has a second arm base (22), a second arm wall (24), and a second arm support surface (26) provided on the second arm wall (24). The first arm support surface (20) includes a first arm recess (36), and a first arm inclined surface (46) which slopes towards the first arm recess (36). The second arm support surface (20) includes a second arm recess (56) and a second arm inclined surface (60) which slopes towards the second arm recess (56). In use the spacer is located on a top surface of a pod to support a reinforcing mesh.