Calculating materials needed for wall footing.

[lutonlagerlout]

where do you get 1.5 m3 from?

the dimensions you gave us you need .5m3 tops =1 tonne of ballast plus 5 bags OPC

LLL

[Probs]

The footings I quoted were just for one part. Adding all the seperate bits together gives me the total I mentioned above.

Sorry for the confusion.

[lutonlagerlout]

cool estimating materials correctly is important,my blokes just screeded a floor of 65m2, at 90 mm thick i estimated this to be 12 tonnes of grit sand and 60 opc. we had about 1.5 tonnes left over and 7 bags of dust
another builder wanted the guy to get 30 m3 of readymix screed delivered,thats over 60 tonne
can you imagine how bad that would have gone?
LLL

[Rich H]

A common mistake for DIYers is to assume that a 'tonne' bag and a loose tonne are the same thing. A tonne bag is rarely greater than 875kg whereas '5t' delivered loose can easily be 5.5t. Yard boys will often put a bit more in the skid bucket than is strictly necessary.

[Mikey_C]

I've got 5T of ballast left over to prove it. Got fed up with ordering two/three/four bags at at time, ordered 7T for the same price as three bags, they delivered nearly 8 and due to my over esitmateing got left with 5T left over.