Master Card formerly Jon Mitchell wrote:

I bet this is the daftest question posted in here for a while!

I need to set a 4 inch square, 2 metre high, metal post into the ground.
The ground is soil. The post will have a switch mounted on the side at the
top, and as such the post will be subjected to daily stress from people
pushing the switch.

The post has been put into the ground by someone in the past, with very
little cement. I think the combination of insufficent cement and lack of
depth into the soil has caused the post to become loose. I am thinking of
using concrete this time, but I have no idea how to make it.

What are the proportions for sand, cement and ballast.

All help appreciated.

Jon

Here, where winter freezing of the ground, depending on amount of
snow cover, can be a problem it is recommended that the cement
not be brought up to ground level. Also that it not be in the
shape of an inverted cone.
I.e. as you dig the hole for the post there is a tendency for it
to be wider at top than lower down.
So, and it does happen here, even without posts in cement 'plugs'
in the ground is that the frost can 'heave' the plug/post upwards
and after a while you have a post even with a heavy accretion of
concrete on it, loose in the ground or even lifting out of the
ground after a 'hard' winter!
My daughter's deck (wooden posts not cemented) is suffering in
that way now; and a neighbour's ended with the outer edge of
their deck with PT wooden posts not set deep enough, about six
inches higher than next to the house, which had posts that didn't
freeze (or heave) to the same extent!
Just a suggestion anyway. Go deep and concrete the 'bottom' of
the post. And maybe use a cross-piece attached to the post set in
the ground? Terry.