Why Patio Bases Need Gravel Before Concrete

Compacted gravel spreads load and helps water move away from the slab. Pouring concrete on soft or organic soil invites settlement and cracking.

Depth depends on soil and climate. Follow a local specification rather than copying a neighbour’s patio blindly.

Run the Gravel Calculator with the sub-base footprint and depth. Run the Concrete Calculator with slab thickness. Add them in the Cost Estimator as separate lines.

If the patio includes a thickened edge or footings, those volumes are extra — note them explicitly.

Patios usually need a slight fall away from the house. That can change average thickness slightly; discuss levels before you lock a concrete order.

Against a house wall, flashing and damp-proof details matter as much as cubic metres of mix.

Confirm access for the mixer truck or pump. Cold joints from delayed deliveries show forever on a patio finish — timing matters as much as volume.

Have forms, reinforcement, and a screed board ready before the truck arrives. A late scramble for tools is when edges go wrong.

Plan curing: keep the slab damp and protected from extreme heat or frost according to the mix guidance. Walking on the slab too early can mark a finish that looked perfect at pour.