There is no safe universal thickness for every driveway. The design needs to suit the vehicles, ground and site conditions. A typical car parking area, a steep driveway and an area used by delivery trucks do not place the same demands on a slab.
What determines the specification?
Tell the concreter what will use it: cars, a caravan, a boat trailer, a work ute or heavier vehicles. Ground preparation and drainage matter alongside slab depth. Soft or disturbed ground, fill, a slope or poor water runoff may change the design. The public crossing can also have separate council requirements.
Questions to put in the quote
- What thickness is proposed for each section, and why?
- What excavation and compacted base are included?
- What reinforcement and joint layout are specified?
- How are edges, garage transitions and drainage handled?
- Does a designer or engineer need to confirm the specification for the intended loads?
A thicker pour alone will not repair an unsuitable base or poor drainage. Ask for the whole construction detail in writing. If heavy vehicles will use the area, disclose that before a price is prepared rather than assuming a standard residential driveway is suitable.
Check the boundary
In Wollongong, Shellharbour and Kiama, confirm which council governs the crossing between your land and the street. Its approval and construction requirements may differ from the private driveway. Read more about planning a driveway and comparing quotes.
Can I choose a number of millimetres myself?
You can discuss a proposed depth, but the construction specification should be checked against the site, expected loads and any approval conditions before work is agreed.