concrete driveways adelaide when planning a concrete driveway, slab, patio or other residential concrete project in Adelaide, you may come across reinforcement specifications such as SL62 and SL72 mesh.
At first glance, the difference may seem small. Both are welded steel reinforcement meshes used in concrete construction, but they have different steel areas and therefore different reinforcement capacities.
So, what is the difference between SL62 and SL72 reinforcement mesh, and which one is better for your concrete project?
The short answer is that SL72 provides more steel reinforcement than SL62, but the correct mesh should be selected according to the engineering design, concrete slab requirements, loading conditions and applicable standards—not simply because one has more steel.
What Is Concrete Reinforcement Mesh?
Reinforcement mesh is a grid of steel wires welded together and placed within a concrete slab.
Concrete performs very well under compression but is relatively weak in tension. Reinforcement helps control cracking and contributes to the structural performance of the concrete element.
In Australia, reinforcement mesh is commonly manufactured and supplied according to relevant Australian Standards, including AS/NZS 4671 for steel reinforcing materials.
Common mesh types include:
- SL62
- SL72
- SL82
- SL92
- SL102
The number in the mesh designation relates to the nominal cross-sectional area of the reinforcing wire in the longitudinal and transverse directions.
What Does SL62 Mean?
SL62 reinforcement mesh is a welded reinforcing mesh commonly used in concrete slabs and other applications.
The “SL” designation refers to a square reinforcing mesh category, while the “62” identifies the nominal reinforcement arrangement.
SL62 uses 6.0 mm diameter wires at 200 mm centres in both directions, providing approximately 141 mm²/m of steel area in each direction.
This makes SL62 a relatively lighter reinforcement option compared with SL72.
What Does SL72 Mean?
SL72 reinforcement mesh is another square welded reinforcement mesh.
SL72 uses 6.75 mm diameter wires at 200 mm centres in both directions, providing approximately 181 mm²/m of steel area in each direction.
Because the reinforcing wires are larger than SL62, SL72 provides a greater cross-sectional steel area per metre.
That additional steel can be useful where the design requires greater reinforcement capacity.
SL62 vs SL72: Key Differences
| Feature | SL62 | SL72 |
| Wire diameter | 6.0 mm | 6.75 mm |
| Nominal spacing | 200 mm | 200 mm |
| Steel area | Approx. 141 mm²/m | Approx. 181 mm²/m |
| Reinforcement level | Lower | Higher |
| Typical use | Residential/light applications where specified | Applications requiring more reinforcement |
| Cost | Generally lower | Generally higher |
The most important difference is the amount of reinforcing steel.
SL72 contains more steel per metre than SL62, so it can provide greater reinforcement capacity when correctly designed and installed.
Is SL72 Stronger Than SL62?
Yes, SL72 provides more reinforcement steel than SL62.
However, saying that SL72 is simply “stronger concrete mesh” can be misleading.
The mesh does not make the concrete itself stronger in every respect. Instead, reinforcement improves the concrete element’s behaviour under tensile and flexural stresses and helps control cracking.
The overall performance of a concrete slab depends on several factors, including:
- Concrete strength
- Slab thickness
- Reinforcement size
- Reinforcement position
- Subgrade preparation
- Joint design
- Loading
- Curing
- Drainage
- Construction quality
Therefore, installing SL72 does not compensate for poor base preparation or inadequate slab thickness.
Which Mesh Is Better for a Concrete Driveway?
There is no universal answer.
The correct reinforcement depends on the driveway’s design and intended use.
For a standard residential driveway, the appropriate mesh may depend on factors such as:
- Vehicle loads
- Soil conditions
- Slab thickness
- Driveway dimensions
- Ground movement
- Edge conditions
- Local requirements
- Engineering specifications
Some projects may be designed with SL62, while others may specify SL72 or another reinforcement system.
Your concreter or engineer should specify the appropriate reinforcement rather than choosing mesh purely based on price.
SL62 vs SL72 for Driveways
For homeowners comparing SL62 vs SL72 for a concrete driveway, it is important to look at the entire slab specification.
For example, a driveway specification might include:
- Concrete strength grade
- Slab thickness
- Reinforcement mesh
- Reinforcement supports
- Subgrade preparation
- Base-course material
- Control joints
- Surface finish
- Curing requirements
Changing from SL62 to SL72 without considering these other components does not necessarily produce a proportionate improvement in driveway performance.
Likewise, downgrading from SL72 to SL62 simply to reduce the quote may be inappropriate if SL72 was specified for the project.
Does SL72 Cost More Than SL62?
Generally, yes.
SL72 contains more steel than SL62, so its material cost is typically higher.
However, the difference in total project cost may be relatively small compared with the overall cost of a concrete driveway.
The total price also includes:
- Excavation
- Base preparation
- Concrete
- Labour
- Formwork
- Reinforcement installation
- Finishing
- Jointing
- Sealing
- Waste removal
When comparing concrete driveway quotes in Adelaide, don’t focus only on whether the contractor has included SL62 or SL72.
Compare the complete specification.
Why Is Reinforcement Placement Important?
Choosing the correct mesh is only part of the job.
The reinforcement must also be positioned correctly within the concrete slab.
Mesh that is left lying directly on the ground before concrete is poured may not provide the intended structural benefit.
Appropriate supports, such as bar chairs or spacers, are used to maintain the specified reinforcement position during placement.
Your contractor should follow the relevant design and reinforcement requirements for the project.
Does Reinforcement Stop Concrete Cracks?
Not completely.
Concrete naturally undergoes shrinkage and movement as it dries and experiences temperature changes.
Reinforcement can help control the width and distribution of cracking, but it does not guarantee a completely crack-free concrete slab.
Proper:
- Joint placement
- Base preparation
- Slab design
- Reinforcement
- Concrete placement
- Curing
all contribute to managing cracking.
This is why a professionally constructed driveway needs more than just good-quality mesh.
Can You Use SL62 Instead of SL72?
You should not substitute one reinforcement specification for another without confirming that the change is acceptable for the project.
If engineering plans, construction documentation or a project specification calls for SL72, replacing it with SL62 simply because it is cheaper changes the reinforcement design.
If you’re unsure which mesh your driveway requires, ask your concreter:
“What reinforcement mesh is specified for my driveway, and why?”
A professional contractor should be able to explain the specification and how it relates to the slab design.
Questions to Ask Your Adelaide Concreter
Before signing a concrete driveway quote, ask:
- Is reinforcement included?
- Is it SL62, SL72 or another system?
- What slab thickness is specified?
- How will the mesh be supported?
- What concrete strength is being used?
- Is base preparation included?
- Are control joints included?
- Does the project require engineering?
- Are council requirements applicable?
- Is reinforcement installation included in the quoted price?
These questions can help you compare quotes accurately.
Final Thoughts
The main difference between SL62 and SL72 reinforcement mesh is the amount of reinforcing steel.
SL62 uses 6.0 mm wires at 200 mm centres, while SL72 uses 6.75 mm wires at 200 mm centres. SL72 therefore provides a greater steel area and higher reinforcement capacity than SL62.
However, more reinforcement is not automatically better for every concrete project. The correct mesh depends on the slab design, expected loading, soil conditions, thickness and applicable engineering or construction requirements.
If you’re planning a concrete driveway in Adelaide, compare the entire construction specification—not just the mesh type. Proper preparation, reinforcement placement, concrete quality, jointing and curing are all essential for achieving a durable result.