Base for lamp-post

[Dan Smithers]

I have just bought a lamp-post for my front garden to replace a small pedestal that had been knocked over too many times. I am planning to make a base for it to stand on using threaded rod and angles buried in concrete.

1. how deep does it need to be?

1. Should I use stainless steel, or will mild be good enough for this purpose?

2. How do I work out how much concrete to mix? considering that bags of cement and ballast are sold by weight and holes in the ground are measured by volume?

thanks

dan

[David Hansen]

On Mon, 10 Nov 2008 16:56:20 +0000 someone who may be Dan Smithers wrote this:-

Not enough information.

How tall is this lamp post? What is it made of? What is attached to what will be the top?

[NOSPAMnet]

A lamp-post for a front garden ? I'm trying to imagine that in-situ

[Dave Liquorice]

Close enough is 1 cubic metre = 1 tonne.

And how exposed to the wind is the location? What would be suitable for a sheltered suburban garden wouldn't be any good up here...

[Bruce]

Don't be ridiculous.

A cubic metre of well compacted concrete weighs 2.4 tonnes. With poor compaction such as you get when pouring concrete into a hole, you should still expect to get around 2.0 tonnes to the cubic metre.

Also, take more care with your attribution, because the words you quoted were not Mr Hansen's. So stand by for some of the usual mock outrage from Mr. H. ;-)

[David Hansen]

On Mon, 10 Nov 2008 17:25:39 +0000 someone who may be [e-mail] wrote this:-

I saw one once, in a house occupied by two friends. An old gaslight, converted to electricity, but an original cast iron one rather than a modern one. It fitted in quite well. I asked the occupants about it and was informed, with a straight face, that the lady of the house had come back from the pub one evening with it over her shoulder:-)

[Dan Smithers]

approx 2m

What is it made of?

It's a modern cast Aluminium shaft. I think that the weight is less important than the leverage offered when the kids try to swing on it.

What is attached to

Would a light be a facetious answer?

A copper framed glazed lantern case that looks like an old gas light.

thanks

dan

[Andrew Gabriel]

For streetlamps, typically they extend into the ground by around

15% of their height above ground, but they are sometimes set into a vertical pipe which does effectively extend the depth. For a relatively short column which you probably have, this figure probably needs to be more than 15%, as much of that will just be in the topsoil which won't provide much of a foundation.

Many years ago, I saw the contractor's spec for lining a long drive with gaslamp style electric lighting. These were done by setting a length of fat pipe vertically, well below ground level in concrete. Pipe hole left empty. When this was set, the lamp column is stood in it, packed in with mortar with almost no cement in it (I think this it to allow it to be pulled out if it has to be replaced). The bit which I particularly liked was that the columns had to be set randomly a few degrees off-vertical, but never towards the road. In the picture of the final result, it looked like a road with gaslamp columns which had been there for over 100 years. The setting of them randomly slightly off-vertical was a very clever design effect.

[pcb1962]

Here you go:

look a bit daft in a suburban street but in a place with the right character shouldn't look out of place.