Thanks for the advice LLL. Do you know if there is anything I can do about what London Stone Paving has said : "Also, in my experience patios laid on concrete bases will retain water and damp patches will pop up. ", or do you think that this might not happen if I lay onto the mortar mix as you have described?
depends if you want shiny or invisible
i have used lithofin MN stainstop with good results in the past for an invisible type sealant
its not cheap though
LLL