@kamundu..stones have a crushing strength of 5kn/mm2 and above.Concrete has strength of 15 to 25kn/mm2 depending on the mix ratio specified in the structural design.

Some quarry stones are weaker than others. Almost all machine cut stones are weak coz its expensive to cut hard stone with machines. Thats why we find machine cut stone in juja but not in the naivasha,nakuru region where the stone is harder.

The hard stones can replace concrete columns based on the architectural and structural design.

Ahsante @rahatupu

@ Kamundu,

You are not alone- i did mine like so ten years ago and has not noted any structural defects. My structural engineer had done his the same way!

@patcho..you dont have to worry if 4 years later there are no signs of cracks. Chances are that you used very strong machine cut stone , you have not used heavy roofing e.g concrete tiles, you havnt used ceramic floor finishes e.t.c.
I have personally overseen g+3 buildings without columns . Structural engineers are important in pulling such stunts coz they ensure design is optimized.

@patcho..welcome