Cost of concrete base

[Hirsty]

Hi..Anyone got a ball-park figure for materials cost for a 50metre square concrete base for a building?

[ajtg1952]

Is that 50 metres square or 50 square metres and what thickness?

[Hirsty]

Area is 50 square meters. 40cm thick

[Flexo]

Google says around 75-125 USD per m2 on average for unspecified thickness. Note that it is possible to build structures with point blocks (like one concrete cylinder every couple of meters, or just a T foundation and polystyrene plastic as base and so forth. Not a builder myself so I am not going to tell you how to do it, just that if you are just going to build a shed you might not need an entire slab.

[TorreDelAguila]

Cost of readymix concrete here is €60 per cubic metre, delivered.

There are different grades/strengths:
eg B/200/25 This means 200kg of cement per tonne of finished concrete, with 25mm granite chips
Hardest mix is normally B/250/... which is 250kg/tonne of cement, i.e. a 3-to-1 mix.
For a solid slab, of whatever thickness, use a minumum of TWO layers of steel reinforcing mesh, well separated, to prevent flexing and cracking.
Take professional advice on all this.

[knowal]

Area is 50 square meters. 40cm thick

That's 20 cubic metres, which if the €60 price is correct could be €1200.

Just being nosy, is this an architect's plan to have a raft?
I expect you know you need a building licence.

[Hirsty]

Thanks all.... Yes aware of legalities, built a few but not in Andalusia..

[fincalospinos]

Just be aware that currently, to obtain a building license for a new house, you will need to submit a project drawn up by a registered architect, which can cost around 5% of the build cost, and in addition you will need a Geotecnic report which will cost around 2K - 3K.
Almost certainly, if you are building on a raft, you will also need to include for steelwork within the concrete base.