How do I fit edging to a path or drive?

Setting a haunched edge to a line and a level so it holds the surface in, and choosing between concrete kerb, timber, metal and pegged edging.

Difficulty: beginner
Time: 4 hr
Read: 4 min
Safety: caution

Short answer

Dig a trench, set the edging on a concrete bed to a taut string line, and haunch it with concrete on the outside face only. The haunching is what stops it moving — an edging bedded but not haunched will tip within a season.

Edging is not decoration. It is the restraint that holds gravel, blocks or a bound surface in place, and it is the reason well-built paths keep their shape for decades while others spread into the borders.

Safety

Check for buried services before digging an edging trench — they often run along the line of a path or drive. Cement burns skin, so wear waterproof gloves. Concrete kerbs are heavy; lift with two people.

Step by step

Set out the line first.Pegs and a taut string for straights, a hose or a marker line for curves. Stand back and look at it before digging — the line is what you will see for years.
Set the level relative to the surface.For gravel, the edging sits slightly above the gravel level so it contains it. For paving, it usually sits flush. Against a lawn, set it just below mowing height so the mower can run over it.
Dig a trench wide enough for concrete both sides.Around 150mm wide and 150mm deep for a domestic path edging, more for a drive kerb. The trench must be in firm ground, not topsoil.
Lay a concrete bed and set the edging into it.50-75mm of concrete in the bottom of the trench, then bed the edging into it while it is workable, tapping down to the string line.
Haunch the outside face.Concrete against the outside of the edging, brought up to about two-thirds of the edging height and sloped away. This is the part that resists the sideways push and it is the part most often skipped.
Leave the inside face clear.The surface material — gravel, blocks, tarmac — butts up against the inside face. Concrete on that side wastes material and reduces the surface width.
For timber, peg on the outside.Treated pegs driven on the outside face, screwed through into the board, tops cut below the board's top edge. Pegs on the inside are visible and get in the way of the surface.
Let it cure before loading.24 hours minimum before backfilling against it and several days before vehicle loading. Loading green concrete pushes the edging out of line permanently.

Tips

Set the two ends first and string between them. Everything in the middle is then set to the line rather than to each other.
Concrete edging comes in straight and radius units. For a tight curve, use short units or setts rather than trying to bend a straight one.
Where an edge meets a lawn, a mowing strip of flush pavers saves strimming the edge forever.

Common mistakes

Bedding edging without haunching it — The bed stops it sinking but nothing stops it tipping. Sideways pressure from the surface pushes it over within a season. Haunch the outside face.
Setting edging on topsoil — Topsoil compresses and moves seasonally. The trench has to reach firm subsoil or the edge settles unevenly.

If it doesn't work

Edging leaning outwards

Cause: No haunching — Fix: Dig out along the outside face and haunch it with concrete, resetting to the line while the concrete is wet.

Edging line looks wavy

Cause: Set unit to unit rather than to a string — Fix: Reset to a taut string line. Small errors between units compound quickly over a long run.

Timber edging rotting at the pegs

Cause: Untreated pegs, or cut ends untreated — Fix: Use treated pegs and brush end-grain preserver on every cut. Expect to replace timber edging eventually — it is a consumable.

Kerb cracked after a car ran over it

Cause: Domestic edging used where vehicle kerb was needed — Fix: Replace with a proper vehicle-rated kerb bedded and haunched in concrete at a drive entrance.

Alternatives

Concrete kerb or edging block: Strongest and the standard for drives. Bedded and haunched in concrete. Heavy and needs cutting for curves.
Timber edging with pegs: Cheap and easy for gravel paths and beds. Use pressure-treated boards with pegs on the outside face. Ten to fifteen years in the ground.
Steel or aluminium edging: Thin, almost invisible, excellent for curves, and pinned into the ground with spikes. More expensive and not strong enough to restrain a vehicle-loaded surface.
Brick or setts on edge: Traditional and attractive, laid on concrete and haunched. Slower to lay and needs a full mortar bed to survive frost.

Questions people ask

Do I need to concrete garden edging in?

For anything restraining gravel, blocks or a drive, yes — bedded and haunched. For a decorative bed edge holding back soil only, pegged timber or spiked steel is fine.

What edging works best for curves?

Steel or aluminium edging bends to a smooth curve and is almost invisible. In concrete, use short radius units or bricks on edge — a long straight unit cannot follow a curve.