On 08/06/2017 20:42, The Natural Philosopher wrote:
On 08/06/17 17:51, Al-W wrote:
It looks like a reasonably full jumbo bag from a decent builder's
merchant.
I'm thinking of a 5:1 mix of ballast to cement. Anyone know how much
cement I need for the whole jumbo bag of ballast?

Thank you,

Al

jumbo bag is about 850kg

so at 5:1 6 bags or maybe 5...


http://source4me.co.uk/calculate_concrete_mix.php reckons 7