Concrete is often reinforced with iron or steel mesh to give it extra strength. While concrete is extremely strong and durable under compression loads, it has a tendency to break under tension. Tension is what causes cracks across long spans of concrete. Iron or steel mesh added to concrete forms a composite that has greater tensional endurance and will last longer. Meshes come in a variety of patterns and wire sizes for different construction purposes.
Wire Mesh Fabrics
For lighter projects, wire mesh fabrics with mesh size up to 2 inches by 2 inches are typically used. Meshes are usually built in square patterns, with mesh sizes (square) in 5/8 inch, 3/4 inch, 1 1/2 inch, and 2 inches. Rectangular sizes include 1 inch x 1 1/2 inches, and 1 inch x 2 inches. The wire gauge sizes range from 21 (fine) through 12 (stiff) from smaller meshes to larger meshes. Smaller mesh sizes and heavier gauges make stronger reinforcement. Mesh fabrics can be galvanized to improve corrosion resistance.
Welded Wire Mesh Reinforcement
Iron rebar is used for heavier construction. Four major classes include rectangular welded mesh in a square pattern for horizontal applications, square pattern with longitudinal supporting wires, welded mesh for vertical walls, and other designs for special applications. Grid sizes for rebar are typically 4 inches to 8 inches square. Rebar can be wired or welded together on-site for added strength.
Slab Reinforcement Mesh
Concrete buildings last longer with custom-made slab reinforcement. There are two basic types of slab reinforcement mesh. Truss-mesh is welded with triangular patterns linking longitudinal wires. Ladder-mesh comes in a variety of rectangular patterns. Sections are cut and fit for particular applications, then joined with other sections by welding, wiring or clipping the sections together. Special sizes and patterns are used to reinforce masonry projects such as cinder block and brick construction.