Patio!

[gurdinloon]

Have moved house, again and the next project is a new patio. There is already one and the slabs have been laid on the soil, no pointing and are right up against the house. I would like to have gravel and random slabs laid instead. I have read the previous posts, but none are for what i would like to do. I also need to know about DPC and how you know where it is in your building. I have an old townhouse with 80's extension and it is from the extension i will be doing the patio. The soil is quite clay like. Do i need drains and soakaways if i do the patio this way?