Mortar for bedding slabs

[roberta1000]

I need to lay 24 600mm slabs for a 12' by 8' shed I have coming. The ground is fairly flat and hard clay and I'm planning to just bed them onto sharp sand/cement mortar. What sort of mix should I be using and about how much materials will I likely need?

I'm going to be using a small cement mixer (one of the electric ones which can take about half a bag of cement. If I tip half a bag of cement in, how many shovels of sand and how much water will I want?

 

[chessspy]

I would recommend digging down a 4" inches at least and putting at least 75mm of drylean to bed on.
If you decide to mix wet mortar to bed on, (not a very good idea in my opinion) The method to mix is to put in half a bucket water first, then a bag of sand, then the dust then another bag of sand then the plasticiser if any, leave to mix see if the consistency is right and adjust with water or sand.
If you put the dust in first it will cling to the drum and you will not get the correct mix.
Leave the mixer empty with water in between mixes, tip out the water at the end of the day and swill out with more water.
If you don't have anywhere to pour the swill, leave it in the barrow overnight and it will have separated and set by morning, pour off the water and knock the slurry out into a rubble bag.
If bedding on drylean, set up two timbers paralell to the long sides to screed off, and bed the slabs on as you come forward, (make sure there is some small fall 1" or so) Use a line to keep it straight, and point in with a trowel making sure it is well pushed into the joints and finish with a jointing iron.

 

[roberta1000]

Thanks for that Chessspy. Any idea what sort of quantities of sand and cement I'm talking about? I want to get it delivered with the slabs.

 

[chessspy]

half a ton of sharp sand and 3 bags of dust.
Remember that sand doesn't go off and you can always pop out for a bag of dust or two.