Cabro Paving in Nairobi: The Base Decides Everything

Cabro almost never fails as blocks

Concrete paving blocks are strong. What fails is what is underneath them and what is holding them in at the edges, and both are invisible the day the job finishes, which is exactly why they get cut from a cheap quote.

What a proper build-up is

1. Excavate to the right depth: deeper for a driveway than a footpath, deeper again on soft subgrade.
2. Test the subgrade. On black cotton it needs more sub-base, or a geotextile membrane, or both. Skipping this is why so much Nairobi cabro ruts within two years.
3. Sub-base, laid and compacted in layers rather than dumped in one lift. A 200mm layer compacted as one is not compacted.
4. Bedding sand, screeded to a consistent depth. Thicker sand does not fix an uneven sub-base; it just moves where the settlement shows.
5. Blocks laid to pattern, cut in at the edges.
6. Edge restraint, haunched kerb or edging. Without it the field creeps outward and the joints open, whatever the block quality.
7. Jointing sand and vibrate, so the blocks interlock and share load.

Miss any of steps 2, 3 or 6 and the paving will fail regardless of what you spent on the blocks.

Falls and water

Paving must shed water somewhere deliberate. A driveway falling towards a house is a genuinely expensive mistake, and we see it often.

We set falls at survey, typically 1:60 to 1:80 across the surface, and confirm where the water is going before laying anything. If there is no outfall, drainage is part of the job rather than an afterthought.

Rates

KES 1,400 – 1,800 per square metre supplied and laid for plain cabro, 1,800 – 3,200 for coloured or 3D. Blocks alone are 750–1,100 per square metre, and the gap between those numbers is the base: which is the part that decides whether you are paving once or twice.