Welded Mesh Explained: Reference Numbers, Sizes and How to Choose the Right One
Welded mesh is one of the most widely used reinforcing products on any building site, yet the reference numbers printed on it, such as Ref 100, Ref 193, Ref 245 and Ref 395, leave many buyers unsure which one they actually need.
This guide explains what those numbers mean, the standard sizes available, and how to choose the right mesh for the job, whether you are pouring a domestic driveway or a structural floor slab.
What is welded mesh?
Welded mesh, also called welded reinforcing fabric or steel mesh, is a grid of steel wires welded together at every intersection. RMS welded mesh is manufactured from cold-rolled deformed wire and joined using electric resistance welding, which creates durable intersections with minimal loss of cross-sectional area. All RMS welded mesh complies with the SANS 1024 standard, with selected types also meeting BS 4482 tensile requirements.
Mesh is laid into concrete to control cracking and add tensile strength across a wide area, which makes it ideal for flat elements such as floor slabs, driveways, surface beds and walls. Because it arrives as a ready-made sheet, it is far quicker to place than tying individual bars.
What the Ref number means
The reference number is the simplest way to compare one mesh with another. In short, the higher the Ref number, the more steel there is in each square metre of the sheet, and the heavier the duty it is suited to. The number relates to the cross-sectional area of the main wires per metre width, so a Ref 395 sheet contains considerably more steel than a Ref 100 sheet. When someone asks for a Ref 245 or a Ref 395 mesh, they are really specifying how much reinforcement the slab needs.
Welded mesh references stocked by RMS
RMS stocks the full range of standard mesh references to support projects of every scale:
| Reference | Typical use (general guidance) |
| Ref 100 | Light-duty domestic work, thin screeds and paths |
| Ref 156 | Light slabs, footpaths and small surface beds |
| Ref 193 | A general-purpose favourite for domestic floor slabs and driveways |
| Ref 245 | Heavier domestic and light commercial slabs |
| Ref 311 | Commercial floor slabs and heavier loading |
| Ref 395 | Structural slabs and industrial floors |
| Ref 500 | Heavy structural and industrial applications |
| Ref 617 | Heavy industrial slabs and demanding loads |
| Ref 888 | The heaviest standard reference, for the most demanding applications |
The reference numbers and the SANS 1024 compliance above reflect the RMS welded mesh range. The typical uses are general industry guidance to help you get oriented. Exact wire diameters, mass and cover should always be confirmed with your RMS branch or your engineer for a specific project.
Standard sheets, rolls and cutting on site
Welded mesh is supplied by RMS in standard sheets of 6 m by 2.4 m, and selected references are also available in rolls, which can be convenient for certain applications and for transport. For health, safety and quality reasons, RMS does not cut mesh to size in the yard, before delivery, or on collection. Where a smaller piece is needed, the mesh can be cut to size on site, which helps reduce waste and makes handling easier on smaller jobs. Remember to allow for laps where sheets overlap, so that the reinforcement stays continuous across the slab.
How to choose the right mesh
The right mesh depends on the load the concrete will carry and the design of the element. For most domestic floor slabs and driveways, Ref 193 is a common starting point, while heavier slabs, commercial floors and structural work step up to Ref 245, Ref 311 or Ref 395, and demanding industrial applications move higher still. Where a structural engineer has specified the reinforcement, always follow the drawing, because the mesh reference, the concrete cover and the lap lengths are chosen for that specific design. If you are unsure, your local RMS branch can talk you through the options, and every branch sells directly to the public, from a single sheet to bulk orders.
Why Choose RMS?
For decades, RMS has supplied reinforcing steel, welded mesh and accessories to construction projects across South Africa, backed by fabrication expertise and reliable service.
Customers choose RMS because of:
- A national branch network
- In-house Cut and Bend capabilities
- Welded mesh manufactured to SANS 1024
- Experienced technical support
- Reliable delivery schedules
- Direct-to-public sales at every branch
Need Help with Your Next Project?
Choosing the right reinforcement can have a real impact on project cost, productivity and programme timelines. If you have a project coming up, the RMS team can assist with product recommendations, technical guidance and quotations.
