A spacer is provided for attachment to a pair of intersecting reinforcement wires to space them from a form. The spacer has a base member having a generally planar shape and two opposite sides, one of the sides having two continuous grooves that extend completely across the base member and that intersect one another for receiving therein a pair of intersecting reinforcement wires, and the other of the sides having a projection that projects outwardly therefrom a preselected distance to space the intersecting reinforcement wires a specified distance from a form. A cover member covers the one side of the base member. The cover member has fastening portions that coact with complementary fastening portions on the base member to fasten the cover member to the base member with the intersecting reinforcement wires sandwiched therebetween to thereby attach the spacer to the intersecting reinforcement wires.