Driveway edging: the part of the job that decides whether the rest of it holds

Driveway edging is the least interesting decision you will make about a new drive and the one most likely to decide how long it lasts. A block paved surface is thousands of individual units held in compression. Take away what is holding them in at the sides and they do exactly what you would expect: they spread. My team and I have lifted plenty of drives that failed for no other reason.

Why driveway edging exists at all

Rigid surfaces like tarmac and concrete hold themselves together. Block paving, resin bound and gravel do not. They rely on being confined. The edge restraint is what does the confining, and it has to be bedded in concrete and haunched behind, into ground that has not been disturbed, or it moves with the load it is supposed to resist.

The mechanism is worth understanding because it explains every symptom further down this page. When a car turns on a block drive it does not press straight down, it pushes sideways. That force travels outward through the whole field of blocks until something stops it. With a proper restraint, the blocks lock against each other and nothing moves. Without one, the outermost course gives by a millimetre or two, the next course takes up the slack, and the drive slowly unpacks itself from the edge inward. The same sequence is described from the other direction in how block paving is laid, where compaction against the edge is the step that puts the surface into compression in the first place.

You can usually see the failure before you understand it. The blocks nearest the lawn start sitting proud, the joints open a few millimetres, sand escapes and weeds arrive in the gap. Everyone treats that as a weed problem. It is an edging problem that has produced weeds, and re-sanding it every spring treats the symptom forever.

The options, and where each one earns its place

The choice is mostly aesthetic once the engineering is right, with one exception. Where a drive runs alongside a lawn or a border with nothing solid behind it, a concrete kerb bedded and haunched properly is the only thing that reliably holds. Block on edge looks better and will do the job against a wall or a path. Against soft ground on its own it is optimistic.

Where the drive meets the road the choice is made for you. That course is part of the vehicle crossing, it has to be built to the highway authority's detail, and it is priced with the crossing rather than with the drive. The dropped kerb guide covers what that involves and who approves it.

What good driveway edging looks like on site

Three things, and you can check all of them while the work is happening.

It is bedded in concrete, not sand. A kerb sitting on sand has nothing to resist against. This is the single most common corner cut, and it is invisible the day after the drive is finished.

It is haunched behind. Concrete brought up the back of the kerb, not just under it. Without the haunch the kerb rotates outward under load and takes the first course of blocks with it.

It goes in before the surface, not after. Edging installed last is decoration. It has to be in place so the blocks can be laid up to it and compacted against it. If you arrive home to a finished drive and loose kerbs waiting by the gate, something has been done in the wrong order.

Edging, drainage and the boundary

Edges decide where water goes, so they get designed alongside the drainage rather than after it. A continuous kerb along the low side of a drive with no outlet turns the surface into a shallow tank. On the clay we work on that shows up as standing water within a season, which is the same fault covered in the planning and drainage rules guide, arriving by a different route.

One practical point about neighbours. The edge is usually the boundary, and a kerb bedded in concrete is a permanent structure. Getting the line agreed before the digger arrives costs nothing. Moving it afterwards costs a significant part of what the edging cost in the first place.