Abstract: A reinforcing strip for a concrete coating for oil or gas pipes consists of wires (1) welded together to form four-sided meshes (2) inclined to the length of the strip, and a straight selvedge wire (4) welded thereto to form along only one edge of the strip triangular meshes (6) incapable of being elongated by tension applied in a pipe coating and winding machine. The four-sided meshes (3) may be diamond-shaped with longer diagonals (7) longitudinal or transverse, or they may be squares. Welded mesh may be used or zig-zag wires welded to each other at adjacent peaks (9) and troughs (10) which may be interengaged or merely overlapped, and the zig-zags may extend longitudinally or transversely.