Specification guide · Driveways
How thick should a concrete driveway be?
By Nathan Carter, owner, Gold Coast Concrete Services. Reviewed October 2026.
Quick answer
Most residential driveways for cars are 100 mm thick with SL82 steel mesh on bar chairs, poured over about 100 mm of compacted road base. Driveways that carry caravans, boats, motorhomes or trucks are usually 125–150 mm thick with heavier SL92 mesh. Saw-cut control joints and correct falls to stormwater matter as much as thickness.
| Use | Typical thickness | Typical reinforcement |
|---|---|---|
| Cars and light vehicles | 100 mm | SL82 mesh on bar chairs |
| Caravans, boats, 4WDs | 125 mm | SL92 mesh |
| Small trucks, motorhomes | 150 mm | SL92 mesh or as engineered |
| Commercial access | Engineer-designed | As engineered |
| Footpaths (foot traffic only) | 75–100 mm | SL72 or SL82 mesh |
Why the base matters most
A driveway is only as good as what it sits on. We excavate soft topsoil and roots, then lay and compact crushed road base to give an even, firm platform. On most Gold Coast blocks this is about 100 mm deep, and more on soft or filled ground.
Skipping compaction is the most common reason driveways sink and crack. The concrete itself is not designed to bridge soft spots.
Steel mesh and where it sits
Steel mesh holds the concrete together if it cracks, so cracks stay tight instead of opening up. SL82 is the standard for car driveways. SL92 has thicker bars and is used where heavier vehicles park.
The mesh has to sit in the right place inside the slab, not on the ground. We place it on plastic bar chairs so it ends up in the lower-middle of the concrete with enough cover to protect it from rust.
Concrete strength
Residential driveways usually use 25–32 MPa concrete from a local batch plant. Higher strengths and mixes designed for salt exposure are used close to the beach, because salt air can reach the steel and cause rust over time.
Control joints
All concrete shrinks slightly as it dries, and it will crack somewhere. Control joints decide where. We saw-cut joints within about 24 hours of the pour, spaced so each panel is roughly square. That way any shrinkage cracks form neatly inside the cut instead of across the middle of the driveway.
Falls and drainage
Every driveway is set with a fall so water runs off to the street or a drain, never back toward the garage. Where the driveway slopes toward the house, a strip drain across the garage opening collects water and takes it to stormwater.
Thickened edges
Edges and the transition to the road take the most wear from tyres. We often thicken the edges and the crossover connection to stop them cracking off.
Common questions
Is 100 mm thick enough for a driveway?
Yes, for cars and light vehicles when it is built on a compacted base with SL82 mesh and proper joints. Go thicker if you park a caravan, boat or truck on it.
Do I need an engineer for my driveway?
Not usually for a residential car driveway. Heavy-vehicle and commercial driveways, and driveways on very steep or unstable ground, may need engineering.
Can you use fibres instead of mesh?
Fibre-reinforced concrete helps control early shrinkage cracking, but we still use steel mesh in driveways because it holds cracks tight under vehicle loads.
Why are there cuts in my new driveway?
They are control joints. They give the concrete a planned place to crack as it shrinks, so the cracks stay neat and hidden.
More on driveways
- What affects the cost of a concrete driveway?
- Exposed aggregate vs plain concrete
- Concrete vs pavers for a driveway
- Driveway crossovers on the Gold Coast
- Concrete Driveways
