Granite kerbs — direct from our quarry in Portugal

The granite kerb, also known as edging or by its trade name lancis, is the most durable way to edge a drive, a terrace, a bed or a lawn cleanly. Quarried and dressed in our own quarry in Portugal, it is solid stone — not a reconstituted concrete or a moulded profile — dense, frost-proof and all but indestructible. You buy direct from the producer: the delivered price is the final price to your door, with no middleman and no carriage charges tacked on at the end. The kerb is sold by the linear metre and comes in a standard 8×20 cm section.

A kerb does two jobs at once: it draws a crisp line between two spaces (say the gravel of a drive and the lawn), and it physically retains the materials in place — sand, setts, topsoil — that would otherwise spread over the seasons. Laid on a concrete footing, it contains the thrust of the surfacing and guides rainwater to the outfalls. Where a concrete edging greys, splits and crumbles after a few winters, granite keeps its crisp arris and its colour for decades. By buying direct from the quarry, you pay for the stone, not the chain of resellers: that is what lets us quote a producer's price, delivery included.

Our grey Portuguese granite is a very hard igneous rock, with a compressive strength above 2,180 kg/cm² and water absorption below 0.2%. In plain terms, the kerb will not crack in the frost, will not distort in the heat and does not stain easily. It is the same stone as our setts and our paving slabs: you can match kerb, drive and terrace in one and the same material, with a perfectly consistent shade.

Laying a granite kerb is within reach of a competent DIYer, but it calls for care over alignment and the foundation. Here are the main principles; if in doubt, call in a paviour or ask us for advice on the quote form.

1. The footing (concrete foundation)

Dig out a trench along the run, then cast a concrete footing (foundation) about 10 to 15 cm deep. It is this that takes the loads and stops the kerb moving over time. Wait until the concrete is beginning to go off but is not fully hard: the kerb is bedded into this still-fresh bed.

2. Alignment to a string line

Set up a string line at the finished height you want and lay each unit to it, adjusting the height and line with a rubber mallet. Check the level and the fall regularly. For a curve, use shorter units and open the joints slightly.

3. The back haunch

On the carriageway or "low" side, cast a back haunch (a fillet of concrete) against the foot of the kerb, up about a third of its height. It is this haunch that locks the kerb against the thrust of the surfacing and the passage of wheels. Without it, the line eventually works loose.

4. The joints

Fill the joints between units with mortar (5 to 10 mm) and strike them off smooth. On a free-draining path, a stabilised-sand joint is an option. Clean the stone before the mortar sets to avoid staining.

5. The fall

Always set the line with a slight fall in the direction of water run-off. Alongside a carriageway, the kerb forms a channel with the surfacing that carries rainwater to the gullies, with no ponding at the foot of walls.