Welded wire mesh (also called welded fabric or mesh reinforcement) is a grid of steel wires arranged at right angles and electrically welded at every intersection point. It is one of the most common and practical forms of reinforcement for concrete slabs, floors, and other flat or lightly loaded structural elements.
Sizes and Specifications
Welded wire mesh is available in flat sheets or rolls, depending on the wire diameter. Common specifications include:
- Wire diameter: Ranges from 4 mm to 12 mm, with 5-6 mm being typical for residential slabs.
- Grid spacing: Common spacings are 100 x 100 mm, 150 x 150 mm, and 200 x 200 mm. Closer spacing provides more reinforcement per square metre.
- Sheet size: Standard sheets are usually 2 x 3 metres or 2.4 x 6 metres. Lighter meshes come in rolls up to 50 metres long.
- Designations: Mesh types are identified by codes such as Q188, Q257, or Q335 (where the number indicates the cross-sectional steel area in mm2 per metre).
Why Use Welded Wire Mesh?
Compared to tying individual rebar by hand, welded mesh offers several advantages:
- Speed: Sheets are rolled out and cut to size, dramatically reducing placement time.
- Consistency: Factory welding ensures uniform spacing, which is hard to achieve with hand-tied bars.
- Cost: For lightly reinforced elements, mesh is generally cheaper than equivalent rebar arrangements.
Application
Welded wire mesh is the go-to reinforcement for residential concrete slabs, garage floors, driveways, pathways, and strip foundations. It is also used in plaster and screed to control cracking. For DIY builders, place the mesh on rebar spacers so it sits in the lower or middle third of the slab thickness — never let it rest on the ground. Overlap adjacent sheets by at least one full grid square (typically 150-200 mm) and tie the overlaps with binding wire.
Related terms
- Reinforcement
- Concrete slab
- Strip foundation
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