Understanding how to prepare your site for a concrete driveway ensures a strong foundation that resists cracking and sinking. A driveway is only as good as the base beneath it.
Steps on how to prepare your site for a concrete driveway
1. Clear and Excavate the Ground
Remove all grass, plants, debris, or old driveway materials. Excavate the soil to the required depth, ensuring there’s enough room for both the compacted gravel base and the concrete slab. The depth will depend on your soil type and expected vehicle load, but typically 150–200mm is needed in total. For sloping sites, make sure you level out the excavation as much as possible.
2. Compact a Solid Base
Spread a layer of crushed rock, road base, or gravel around 75–100mm thick. Use a mechanical compactor (plate compactor or roller) to firmly compress the material, repeating in layers if needed. A properly compacted base distributes weight evenly and prevents the driveway from sinking or developing soft spots.
3. Install Proper Drainage
Driveways must slope away from buildings to prevent water from pooling near your home’s foundation. Aim for a minimum slope of 1–2% (about 10–20mm per meter). Consider adding drainage channels or soak wells if your property is prone to heavy rain or poor natural runoff. Good drainage not only extends the life of the concrete but also keeps the surface safe and slip-resistant.
4. Build Strong Formwork
Set up sturdy timber or steel formwork to outline the driveway’s exact shape and dimensions. Ensure the forms are level, well-secured, and straight, as they act as the mold that holds the wet concrete in place. Double-check alignment with string lines or a laser level to avoid uneven edges or crooked lines once the concrete sets.
Pro Tip: The majority of driveway failures trace back to poor site preparation, not the concrete itself. Taking the time to properly excavate, compact, and set drainage can save thousands in costly repairs later. Think of it as building the backbone of your driveway—the stronger the foundation, the longer it will last.