Tim W wrote:
[...]
Oak because there is a local sawmill which cuts a lot of green oak
for
fencing and building. They have mountains of offcuts. My instinct
is
telling me that if they are not as thick as they are wide they will
curl up so maybe 3" or 6" cubes would be the thing.

I can't find any web references to garden use, only a few to old
street cobbles. I don't know yet if I have had a brilliant and
original idea or if there is a very good reason why this is never
done.

Been thinking about it some more, and I think they'd have to be
absolutely soaked in preservative: oak's good, but it's not _that_
good. As it's short end-grain pieces the stuff should soak in well;
but only after the wood's well dried; and I think it would tend to
wash out, so you might have to re-treat as often as every year, right
during the long dry spell when you most want to sit out on it. You'll
want very good drainage underneath, too.

I'm becoming a little sceptical. I still think it's a great idea,
though.

--
Mike.