How we build a driveway
Every driveway that fails looked perfect on the day it was finished. Here's what's underneath ours, and why we photograph all of it before it disappears.
It doesn't fail at the top
Both of these were four years old.
The seven stages
Stage 1
Set out and levels
Marking the area and establishing the finished height and the falls before anything is dug.
BUILD RECORD PHOTO — Set out and levelsStage 2
Excavate to depth
Down to at least 150mm below the damp proof course, and deeper where the ground is soft.
BUILD RECORD PHOTO — Excavate to depthStage 3
Geotextile membrane
Stops the sub-base migrating into the subsoil underneath. Cheap to include, and one of the first things left out of a low quote.
BUILD RECORD PHOTO — Geotextile membraneStage 4
MOT Type 1 sub-base
Laid in 75mm loose layers and compacted separately, building to 150mm compacted for a domestic drive. Type 1 loses roughly 20% under compaction, so about 180mm loose gets you 150mm finished.
BUILD RECORD PHOTO — MOT Type 1 sub-baseStage 5
Edge restraints
Haunched in concrete, not bedded on sand. Without this the whole drive slowly creeps outwards and the joints open.
BUILD RECORD PHOTO — Edge restraintsStage 6
Laying course
50mm of sharp sand, screeded level. Sharp sand, not building sand.
BUILD RECORD PHOTO — Laying courseStage 7
Lay, cut, compact, joint
Blocks laid slightly proud, whacked down, then kiln-dried sand brushed into every joint.
BUILD RECORD PHOTO — Lay, cut, compact, joint
What a cheap quote leaves out
- No membrane
- 75mm of sub-base instead of 150mm
- Edges bedded on sand instead of haunched in concrete
- Building sand instead of sharp sand for the laying course
- One thick layer of Type 1 instead of compacted 75mm layers
Every one of those is invisible on handover day. Every one of them is why driveways fail.
Where the water goes
A driveway has to shed water. We build in a fall of roughly 1cm for every 60cm of length, away from the house, so surface water leaves the drive instead of sitting in the middle of it or running at your door. Where there is nowhere for it to go, we use a permeable build-up or a channel drain into a soakaway.
The planning rule is simple. You do not need planning permission for a permeable surface of any size, or where the run-off is directed to a lawn or a border. You do need permission for more than five square metres of impermeable surfacing that drains onto the road.
The build record
At the end of the job you get a PDF. Photographs at set-out, excavation, membrane, each sub-base layer, compaction, edge haunching, laying course and finish, with the depths measured, the materials named and the dates recorded. It is the only evidence that exists of what is under your driveway once the blocks are down.
[EXAMPLE BUILD RECORD PDF — to be added]