In article ,
Paul Kelly wrote:
"Nick Maclaren" wrote in message
...
In article ,
janet.bennett wrote:
Yes, I saw the new gardening programme last night, but unfortunately they
don't quote the number of bags and sand and cement you need. Thanks for
advice.

But my advice is NOT to use concrete at all! If you build a pergola
properly, it will support itself and you will not have trouble with
the concrete when planting or removing it.

Possibly, but you need to define "Properly"! ie crossmembers properly
jointed and srtucural corner bracers etc etc the top structure is then
locked and solid.

I thought that he was asking about a pergola, not a component of an
assault course! No, I am not referring to that - all I have ever done
is to nail or screw the members to each other.

But IHMO that is all too much faff. Concrete in 4*4 verticles to 75cm and
bolt or screw the horizontals and you can forget about all the proper
jointing and cross bracing.

And then go and buy some plastic climbers to put up them - the curses
of the people who buy your house are not your concern.


I have built four such structures in the way that Colin Bignell and
I describe, and they never shifted. A couple were there for a decade
or so, too. The three that are still up are showing no signs of
movement - flexing, yes, but not permanent movement.

Oh, and I do climb on them when needing to do major work on the top,
and their flexing is small enough not to worry me, which is saying
something (I have very little middle-ear function).


Regards,
Nick Maclaren.