Ballast, Sand, Hardcore and Murram Supplied in Nairobi

We price per tonne, and here is why

Kenyan aggregate is almost always quoted “per lorry” without anyone saying what the lorry is. A seven-tonne Isuzu and a twenty-two-tonne trailer are both a lorry. Quotes that appear to differ by a factor of three usually do not differ at all once you divide by the payload.

Work through the published figures and they collapse into one band:

• Grade A machine-cut ballast at KES 40,000 for a 22-tonne trailer is about 1,820 per tonne
• Grade B hand-cut at KES 30,000 for the same trailer is about 1,364 per tonne
• “A lorry of ballast for 12,000” on a 7-tonne Isuzu is about 1,714 per tonne

Nothing there was wrong. The unit was missing. Ask every supplier for a tonnage rate and a stated payload, and the comparison becomes possible in about a minute.

Machine-cut against hand-cut ballast

Machine-cut is graded to a consistent size and comes clean. Hand-cut is cheaper, more variable in size and carries more dust.

For structural concrete you want machine-cut. Variable aggregate size changes the water demand of the mix batch to batch, which changes the strength, and the dust coating on hand-cut stone gets between the aggregate and the cement paste, which is exactly the bond the concrete depends on.

For mass fill and blinding, hand-cut is perfectly reasonable and the saving is real.

Sand is priced by geography, not just by quality

River sand costs what it costs mostly because of distance from the source and the county levies on the way. Two loads of identical material can differ substantially depending on which river and which route. Anyone claiming a large price advantage on sand is usually telling you about their haulage, or about the sand not being what they said it was.

Watch for salt in sand sold near the coast and for excessive silt in cheap river sand. A silt test takes a jar, some water and twenty minutes, and it is worth doing on a large order.

Hardcore and murram: transport is the cost

Both are cheap materials with expensive haulage. The rate before transport tells you very little, because on most Nairobi sites the transport exceeds the material. We quote delivered, to the site, so the number you compare is the number you pay.