In article ,
"CWatters" writes:
|
| Google says the density of concrete is about 2400 kg/m3 so it looks he
| needs 7200 Kg or 288 x 25 Kg bags! (Actually less than that if you allow for
| the water. Either way I wouldn't want that in the back of my car :-)

Google says many things that aren't so. A specific density of 2.4 is
a very dense concrete, of the sort used to make paving slabs - completely
overkill for a greenhouse base.

| Lets say his house is 4 x 3 M and 150mm thick = 1.8 cubic meters. .So 3
| cubic does sound a lot.

150 mm thick is also overkill.


Regards,
Nick Maclaren.