Installation
How to cut and bend welded wire mesh on site
Cut welded wire mesh with 24 to 36 in (600 to 900 mm) manual bolt cutters or a cordless abrasive cut-off wheel. When bending mesh for corners or grade beams, maintain an inside bend diameter of at least 4 times the wire diameter (4 d_b) and keep all bends at least 25 mm (1 in) away from welded intersections per WRI WWR-400 to prevent weld shearing.
Cutting welded wire mesh on site
Standard welded wire mesh sheets are made from high-strength cold-drawn carbon steel with yield strengths between 450 and 550 MPa (65 to 80 ksi). Choosing the correct cutting tool depends on wire gauge and volume:
| Cutting Tool Option | Best Wire Gauge Range | Cutting Speed | Job-Site Advantages & Practical Limitations |
|---|---|---|---|
| Manual bolt cutters (24 to 36 in · 600 to 900 mm) | 10 gauge (3.43 mm) and 6 gauge (4.88 mm) | Moderate (cut by cut) | Portable; requires no electricity or battery; leaves no hot sparks or burrs |
| Cordless angle grinder with 1 mm thin cut-off wheel | 6 gauge (4.88 mm) and 4 gauge (5.72 mm) | Fast (slices full rows) | Rapid gang cutting across multiple wires; requires eye protection and spark control |
| Heavy-duty pneumatic or hydraulic wire shear | All sizes up to W20 (12.8 mm) | Very fast | High production for precast plants; expensive industrial equipment |
| Reciprocating saw with metal-cutting blade | 6 gauge and 4 gauge | Slow | Good for tight enclosed spaces; vibrates loose wire ends if unsupported |
For typical residential slabs and driveways, a pair of 24 in (600 mm) compound-action bolt cutters is the most reliable, spark-free tool for trimming 6 gauge (6×6 W2.9/W2.9) sheets around sewer cleanouts, grade beams, and slab perimeter forms.
Step by step sheet cutting procedure
- Measure from outer wire nodes: When trimming a sheet to fit within formwork, account for edge clearance. CSA A23.1 requires maintaining 50 to 75 mm (2 to 3 in) clearance between reinforcing steel and formed slab edges.
- Snip wires close to intersections: When trimming excess sheet width, cut the wire roughly 12 to 25 mm (0.5 to 1 in) past the welded intersection. Leaving a short stub prevents the weld from peeling if edge wires are bumped during concrete placement.
- Safety control: Flying wire offcuts are sharp and under tension. Always wear leather work gloves and safety glasses with side shields when cutting wire mesh.
Bending rules and minimum bend diameters
Contractors often need to bend welded wire mesh into L-shaped corner returns, U-stirrups for grade beams, or continuous downturn edge reinforcements.
Because cold-drawn wire has lower elongation than ductile hot-rolled rebar, bending wire too sharply or bending across a welded node can cause premature wire fracture or weld shear.
The Wire Reinforcement Institute Manual on Bending Welded Wire Reinforcement (WWR-400) sets out two mandatory rules:
1. Minimum inside bend diameter (4db to 6db)
- For wire sizes up to W6.0 (6.0 mm · 0.276 in diameter, including 4 gauge and 6 gauge): The inside diameter of the bend must be at least 4 times the wire diameter (4db).
- For 6 gauge wire (4.88 mm · 0.192 in), the minimum inside bend radius is 10 mm (bend diameter 20 mm · 0.77 in).
- For 4 gauge wire (5.72 mm · 0.225 in), the minimum inside bend radius is 11.5 mm (bend diameter 23 mm · 0.90 in).
- For heavier structural wires (over W6.0): The minimum inside bend diameter increases to 6 times the wire diameter (6db).
2. Distance from welded intersections (The 25 mm rule)
Welding generates localized heat that alters the microstructure of cold-drawn steel directly adjacent to the weld nugget. Bending directly through a weld will pop the joint.
Under WRI WWR-400 and ACI 318-25 Section 25.3, all bends must be positioned so the start of the bend is at least 25 mm (1 in) or 4 times the wire diameter (4db) away from the nearest welded intersection.
Field bending equipment
- Hickey bar or manual rebar bender: A standard manual bending tool can clamp over individual wire extensions to create clean 90-degree corner returns.
- Job-site timber bending brake: For bending full 2.44 m (8 ft) sheet widths, crews sandwich the sheet between two straight 2×6 or 4×4 timber members clamped securely with C-clamps, then use a third timber lever to bend the projecting wire uniformly along the entire edge.
- Wire Reinforcement Institute (2026), Manual on Bending Welded Wire Reinforcement: For Reinforcing Concrete Structures (WWR-400). Link
- Wire Reinforcement Institute (2026), Manual of Standard Practice: Structural Welded Wire Reinforcement (WWR-500-R-26). Link
- ACI 318-25, Building Code Requirements for Structural Concrete. American Concrete Institute.
- CSA A23.1, Concrete materials and methods of concrete construction. CSA Group.
Questions
What is the best tool to cut welded wire mesh?
24 to 36 in (600 to 900 mm) bolt cutters are best for 6 gauge and 10 gauge mesh; a cordless angle grinder with a thin metal cut-off wheel is fastest for heavy 4 gauge sheets.
Can you bend welded wire mesh by hand?
Light 10 gauge wire can be bent over a straight timber edge by hand wearing heavy leather gloves. Heavy 6 gauge and 4 gauge wires are too stiff and require a bending bar, hickey bar, or mechanical brake.
Why did my wire mesh weld break when I bent it?
You bent the wire directly on or too close to the welded intersection. Keep all bends at least 25 mm (1 in) away from welded intersections per WRI WWR-400 guidelines.
How much clearance should wire mesh have from the slab edge?
Keep reinforcing mesh 50 to 75 mm (2 to 3 in) back from exterior formwork to prevent steel from being exposed to moisture and salt at slab edges.