wrote in message
oups.com...
thanks Rob

I didnt even think about turning over the existing lawn and using the
material, but its an obvious solution. I was thinking transplant the
existing lawn, or using completley new materail and reseed.

I think I'll go with your option of using the existing soil and
turning the grass into the hole.

Can anyone suggest how deep the top surface should be ? I assume if
its too shallow the water will drain away too quickly.

3-4 inchs of decent brown soil minimum likely. Having said that, as deep as
you can get it through reasonable excavation. You need not be too worried
about mixing soil up, though avoid it if possible.That is, don't put clay on
the surface but you can't help mixing stuff up a bit. If excavating the new
patio area you find you have a shitty little layer of good top soil and then
clay you could try filling the hole with organic matter such as well rotted
compost and then the layer of sod over the top. Make the best of what you
have unless you have sfa, if that makes sense. Overfill the hole about 1
inch to allow for compaction.

rob