You take the fence post out, you put the fence post in

[David WE Roberts]

Out, in, out, in, then you hit the gin.........

Started on the fence replacement project and the old shortish concrete posts which had wooden posts bolted to them are proving a bu**er to get out.

They have a lot of concrete below ground and to get them out I need to dig around a bit, then rock the post until it will tilt, and then gradually drag the whole sorry thing out. The posts with the concrete added weigh a significant amount and I am ending up dragging them along the ground (more of them later).

This leaves an ugly hole about a foot deep and very wide. What I want in the same location is an 8" wide hole 18" deep, to take the new post and the concrete around it.

At the moment all I can see to do is fill the hole in, with much tamping down, then dig the 8" hole in the middle of the newly filled in larger shallower hole.

Does anyone have a better way to do this?

[I thought of shuttering some of the hole and using a little extra post fix (at under £4 a bag this is not an expensive option compared to using half a day filling in and digging out) but I am not sure that the last bit of the narrower hole (perhaps 6") will be enough to hold the new post upright until everything has set, when I can remove the shuttering and back fill the hole.]

Why not use the old posts? Well, they are not very straight. In fact some are leaning over at quite an angle. Given the amount of concrete around the base of the one I have taken out it makes me wonder how robust the new posts will be. The old post (once I had removed a few inches of soil around it) rocked about alarmingly easily. Also note that some of the old posts are leaning over already.

I am starting to wonder if I should hire an engine hoist to lift the old posts out - with a strong lift they should come out like a rotten tooth. This would also reduce the size of the hole from the extraction.

Any advice gratefully received.

Cheers

Dave R

[RubberBiker]

Hitch a rope around the old post (fairly high up), then use a farm jack to pull them out.

Because you can apply pressure with the jack high on the post, the force is in exactly the right direction to tug it out.

I injured my back by bear-hugging most of them out, *before* I bought a farm jack and did it the easy way.

far as churning up the ground, just accept it will happen.

If the holes are large, hire a cement mixer and make up concrete and tip a barrowload into each place.

Deep, deep holes and concrete right at the bottom is what keeps posts vertical. One third of the post underground for very exposed locations, or very poorly compacted ground.

[The Natural Philosopher]

Mini digger. Dig around them , use th bucket to push a bit and work loose, then a strap around and use the bucket to hoick out and the digger can then drag.

I pulled out tree stumps all over an acre of land using a digger. Mind you stumps are shallow and broad - the key was to dig around and snap all the lateral roots. The odd one needed an axe on it.

And a digger makes light work of re-modelling teh landscape too. You can redistribute soil, and use the front blade to more or less level it.

No garden should be without one. Also good for making new flowerbeds. And destroying moles habitats

[george (dicegeorge)]

what about hammering a metal spike down in the hole then pouring the concrete around it so its sort of like reinforced upwardly-ish?

[g]

[David WE Roberts]

Interesting suggestion - only problem I see is that it is not just the post I have to lift, but a wide plug of concrete around the base as well. This suggests that I would have to position the jack 4"-6" away from the post which I guess means that I would have to fashion some kind of framework for the post to transfer the lifting force.

The ideal solution seems to be an engine lift (chain hoist) and a tripod but this looks to cost over £100 for the week.

Hiring a cement mixer and making up loads of cement is also likely to be expensive by the time all the materials have been costed in. I am looking for a cost effective way - the best I have so far is to make up some kind of framework (or find a 200mm+ diameter pipe) and fill in around that, thus avoiding the filling in and digging out of the central hole.

[neverwas]

Are you worried deeply about the environment and landfill? If not, can you source (eg from local builders or decorators) some empty 10 or (better) 15 litre plastic paint pots? Cut bottom out and use as your "mould". Back of Excel calcn suggests 15l is a little less than your

8x8x18 inches (which I make to be about 19 litres) but as others have said you get added benefit from the mass being lower.

One other thought: make your mix weak if you think you (or anyone you love) might want to remove your posts. I learnt that lesson from uk.d-i-y only after putting in 10 concrete posts a while back. I now hope desperately the posts outlast me as I stupidly used a strong mix that goes rather deep.

[Tim S]

The Natural Philosopher coughed up some electrons that declared:

Just for teh record, how big was the digger?

[David WE Roberts]

Minor problem - how do I get the digger behind the shrubbery?

A new/clear site would suit a mini digger (plus loads of fun to be had) but this is a mature garden.

I have cleared a passage between the shrubs and the fence wide enough for me to get through, but no way would I get a digger in there.

Besides, it is unlikely to be cheaper than a hoist to hire.

This is a slow project because I am replacing the fence but keeping as much of the old fence as possible in place - can't just slash and burn the whole lot and amalgamate our garden with the next door neighbour's.

[David WE Roberts]

Thanks - I was looking at 200mm pipe but this appears to be concrete and therefore likely to be very heavy.

As a first attempt I will use a large plant pot with the bottom cut out and fill around that - this should get enough depth to be able to hold the post and I can then work my way upwards by resting the plat pot on the first lot of postfix and filling around it again.

[David WE Roberts]

Well, what do you know!

Next post in line had no concrete at all around the base.

By the use of a long pole, rope, and the principle of fulcrums and levers I managed to extract it (with my beautiful assistant jamming the post to stop it sliding back as I repositioned the rope).

I could even pick the whole thing up and shift it - amazing the difference a lump of concrete on the end makes!

I am now hoping they concreted in only every other post (or less).

Murphy's law suggests that the nice deep round hole that the post left will be just a few inches away from where I want to put the new post.

[Cicero]

=================================================

If you want a farm jack they're cheaper here:

think an engine hoist would be quite dangerous in your situation on soft ground - likely to fall over unless very firmly supported.

As an alternative to lifting the posts / concrete out you could break them into smaller pieces for re-use as hardcore. A breaker is quite cheap to hire.

To fit your new posts you need some hardcore packing around the bottom of the posts at the bottom of the 18" deep hole. The hole should then be filled to within about 8" of the top with compacted soil. This should be topped off with a wide and deep topping of concrete about 12" diameter. It is the diameter and bulk of this top layer which will prevent the posts rocking.

Cic.

[The Natural Philosopher]

I think I sued a 3.5 tinne for that exercise.

Mini diggers might just cope with fence posts.

[The Natural Philosopher]

Over or through it..;-)

Mmm. My wife was horrified at the mess left behind 'relax' I said 'in a year it will all be grass' It was.

Shrubs take a little longer, but 3-4 years is enough to get most back to where they should be.

Its more fun though. About £100 a day.

Sometimes fiddle and fit is more expensive than trash and replace.

I spent about 6 hours modelling a bit of kitchen to fit an existing cupboard 'because I like it'

It would have been easiier to build a new one nearly the same..

[RubberBiker]

In practice, they'll find a way past each other. In extremis, you could put down a few bricks either side with a board across, and sit the jack on that.

Not really, compared to postcrete.

You'll just end up with a heavy post that way - it won't be tight up against undisturbed ground. One good shove (or high wind) and it'll displace the in-filled ground around it.

[Fredxx]

What's wrong with using a collection of scaffold poles, with putlocks, to create a tripod.

Using padstones and wood for each foot, and a block and tackle, I would have thought they would have pulled out vertically quite easily.

[Lobster]

Do they *have* to be in the same location? As in, couldn't you site the first post a couple of feet back along the fence... that way all the new posts would be offset against the positions of the old ones, which you wouldn't need to remove, just chop them flush with the ground[1]

David

[1]But not using a circular saw blade on an angle grinder... (qv)

[nightjar]

You can get it in grey uPVC, but I suspect it would be cheaper and I am sure it would be more secure, just to refill the old hole with new concrete.

Colin Bignell

[The Medway Handyman]

Very often fences are not exact multiples of panels e.g. 4.5 panels. If you shift the half panel from one end of the fence to the other the fence line remains the same but the new posts are 3' away from the old ones.

[Harry Bloomfield]

David WE Roberts was thinking very hard :

How about something similar to a pair of trolley jacks, with a bar across to do the lifting?

[<me9]

And like Grandad's step, Someone did it 20 years ago!