The message
from Iain Robinson contains these words:

I posted here earlier in the week and some kind souls pointed me in the
right direction, clarifying what I should lay my patio on. But I need a
bit more clarification please.

After whacking down my sub-base I am putting down a drymix mortar to lay
the slabs onto. It seems one part cement to four parts sand is the right
ratio - correct? I had read that the sand for patio work should be sharp
sand (as it 'locks' in place) but I see that pavingexpert.com recommends
that soft sand be used for mixing up mortar. Which is correct?

Save yourself a lot of grief, do it the proper way first time.

www.pavingexpert is run by an ex-urgler expert with a national
reputation for the quality of his professional work. He does
award-winning work for the National Trust etc. Having followed his
excellent website advice myself I can absolutely recommend it; you can
also ask for personal help via his website iirc.

Janet.