Measuring ballast and cement....

[scadding]

I am about to lay a 100mm shed base using a cement:ballast ratio of 1:5.

First question.... Is that the recommended ratio?

Second question.... Because of limited access the ballast and cement will be delivered (Wickes) in 25 kg bags. Is the mixing process as simple as mixing 1 bag of cement with five bags of ballast (ie a weight ratio) or should I tip the contents into buckets so that the 1:5 ratio is measured by volume.

I can easily do both so which is the correct method??

Thanks in advance......

 

[noseall]

Mix it 6:1.

Six 25kg bags of ballast to 1 x 25kg bag of cement should be near enough as long as you have a mixer big enough!

 

[scadding]

The shed is a metal shed which will house just a sit-on mower. Unfortunately the ground is not level therefore the shuttering is 100mm high on two sides, increasing to 200 mm on the other two sides. Will it be necessary to use hardcore given the limited weight of the shed, or will it be ok to fill the whole area with just concrete.
I'd appreciate your opinions.....Thanks