Hardcore / sub base needed for 2 x 2 feet concrete slabs?

[pickledherring]

The title says it all really. I have a relatively small area of garden which needs to be covered over with seven concrete slabs, which gives a total surface area of about 2.5 square metres.

The area to be covered is a bare area previously covered by a garden shed that the previous owner of our house had erected, but did not bother to pave underneath.

The surrounding area is already covered with 2 x 2 feet concrete slabs. With such slabs do I need to lay down any hardcore or other supporting material? Would it be sufficient to just compact the soil and lay down four blobs of mortar per slab before bedding in the slabs? the area will not have a new shed on top or anything heavy. Perhaps a barbecue in the summer.

Thanks in advance.

 

[angelboy]

evertything you need to know is here.

http://www.pavingexpert.com/layflag1.htm

 

[r896neo]

The premium job would be 100mm compated sub-base and 50mm bed of mortar. Fulll bed not dabs.

If its 2x2 council flags you'd probably get away with just digging it out and putting in a solid bed of 50mm deent mortar. Something like 6:1

Dots dabs or spots of any kind are crap and will fail quickly and make pointing a fun job every two years.

Its up to you how much effort you want to put in vs long term expectation but if the ground hasnt been disturbed in a good while the mortar only approach will last a good few years.

 

[pickledherring]

Thanks for the advice. I decided to dig down to about 10cm, with about 5 cm of hardcore and the rest made up of ready mixed mortar. See attachments. I'm only responsible for seven of the slabs on the right hand side of the images, which you can see because they are cleaner than the rest. The others were already there, put in place by a previous owner and some are subsiding. These will be dealt with when time permits.

This is my first attempt at such a job, so I accept it's nowhere near perfect.