Driveways in Nairobi: Cabro, Concrete or Both

Thickness follows the traffic, not the budget

• 50mm is a footpath and patio block. Put it on a driveway and it cracks under a car.
• 60mm is the standard domestic driveway block. Cars, occasional light vans.
• 80mm is for commercial traffic, lorries, and anywhere vehicles turn on the spot rather than driving straight through.

That last point catches people out. It is not the weight of the vehicle that breaks paving so much as the twisting load of a wheel turning while stationary: which is exactly what happens in front of a gate.

We specify 80mm at gate aprons and turning areas even on domestic driveways, and we would rather explain why than lay 60mm everywhere and be called back.

Cabro or concrete?

Cabro flexes with minor ground movement, is repairable in patches, can be lifted and relaid to reach a service, and looks better. It needs a proper base and edge restraint.

In-situ concrete is a single rigid slab. It is cheaper over large plain areas, takes heavy static loads well, and when it cracks, which on black cotton it eventually will, the crack is permanent and visible.

For a Nairobi domestic driveway we recommend cabro almost every time, and the ability to lift a section to reach a buried pipe is a bigger practical advantage than most clients expect.

Falls, and where the water goes

A driveway must fall away from the house. On sloping Kitisuru and Lang’ata plots the natural fall frequently runs the wrong way, which means a channel across the head of the drive and a route to a soakaway or a gully.

We establish the outfall before quoting. A driveway with nowhere to send its water is a driveway that floods a garage.

Long approaches

On Karen and Runda plots a driveway can run sixty to a hundred metres. That changes the arithmetic: falls have to be managed over distance, edge restraint runs both sides for the full length, and the volume of excavation and cart-away becomes a significant line of its own.