Dear architect

I need some advise on a foundation slab. The structure is a mansionnete with 90 sqm on the each floor. There is only ! upper floor total area 180 sq m.

The subsoil on the place is only 8 inches thick before hitting the rock layer. The rock layer is a compact piece and from the samples it looks like the one from which quarry stone is made from.

Question
How would the rock substructure influence or reduce the cost of my slab.

Secondly would this mean that I can make my slab smaller etc?

please advice

regards

lynx

As explained, you should just be glad that your foundation will cost less. Slabs should be the same. Some quack might tell you different story .... don't listen to them

better have a structural engineer go over your houseplans. For storey houses, a six inch concrete slab on top of the hardcore (on ground floor)is prefferable. You can also use hollow bricks covered with kokoto sand and cement mixture for the first floor slab.... Very economical.

low buildings do not need deep foundations. Your 8 inches of excavation is just adequate. But pray...the width of the structure is not like some narrow gorofas i see in waitiitu's constitutuency