Putting in a new wooden fence post, concrete it in place?

[MM]

For a couple of years the back fence (8 ft high) has been getting increasingly wobbly in the wind, as one of the fence posts is loose in the ground and allows the fence to move in the wind. The post may either have rotted, or maybe just the movement caused by the wind was enough to loosen it more and more.

So I'm going to get a new, treated fence post on Saturday (from e.g. Baytree or Andrews) and will place it near the loose post.

I plan to dig the hole for the new post using my grubber, spade, garden fork and whatever else that comes in handy. (I also have a crowbar.)

I won't have much room to work, because, of course, the posts are tight up against the fence.

Now, putting the new post in: Would it be best to prop it up so that is properly vertical, then fill around the base with concrete?

Or should I just fill the hole with the earth I removed and tamp it down?

And how deep should the post be inserted into the ground? These are very sturdy posts (10cm x 10cm). None of the others shows any sign of becoming loose; just this one particular one.

MM

[Chris Hogg]

IIRC the recommendation is that a post should be half as deep in the ground as the fence is high. i.e. a 6ft fence should have its posts buried 3ft deep. I find this a council of perfection and difficult to achieve in reality, so get as near to it as you can.

As for concreting, use postcrete^ or postmix*. This is a dry concrete mix, that you just pour as powder into the hole around the post, tamp and shake it down to compact it a bit, then water it well with a hose or watering can. It sets firm in a few minutes. It's a good idea to have the concrete coming up a bit proud of the surrounding earth, by an inch or so, and finishing off the top surface with a trowel so that rain water runs off, away from the post. This helps keep the post from getting too wet and rotting. ^

[harryagain]

Bad idea having posts underground at all.

[harryagain]

Bad idea having any part of the post under ground, it will just rot off again. Get one of the metal post holding devices either a spike or the concrete in ones. Posts last much longer

This sort of thing:-

There are various sorts/sizes.

[Brian Gaff]

What is the fence like? Is it solid featherboarded fence, or something with holes in it.

I made the mistake of cementing in my posts when i did it and within five years i had some rotteed posts as the cement around the posts makde a nice receptacle for water s the posts shrunk.

The replacements are nw in the soil, but as I can no longer do the job, I'm not sure how far the guy put them in.

Brian

[Scott M]

That'll work for about 2 mins before it wobbles the hole bigger again.

I go for concreting in one of the repair spurs (short concrete post) with a wooden post bolted to it. That way, next time round, I can change the post in 10 minutes flat.

[Tim Watts]

I had my fence replaced professionally.

The technique they used (with concrete posts, but same with wood) was:

Dig hole, as tight as possible with a post shovel (long and thin).

Drop post in and position.

Fill with *damp* (not wet) concrete mix. It should be only just damp.

Ram damp mix down whilst holding post vertical and in place.

When you've rammed it the post will stand by itself, which it will not do if the concrete is wet.

[Ian Jackson]

In message , harryagain writes

Look also for 'Metpost'. I put up 14-panel 5' fence using Metposts in the mid 80s, and there's no sign of it falling down yet. It saves a lot of messing around with concreting posts in. And when the time comes to replace them, there are pretty easy to get out.

[MM]

Lots of good suggestions in this thread. I now need to do some more thinking, plus looking at those Metpost type thingies.

One question right now: What on earth is a post shovel? (I can probably Google it, though...!)

Thanks all.

MM

[MM]

Solid featherboard (on neighbour's side). My side is the side with the posts. It's a very sturdy fence. There are 40 properties here, built ten years ago, all with the same fencing. It's just this one particular fence post that has become loose on my fence (sod's law!)

MM

[MM]

Further down the thread, someone mentioned a post shovel and I've googled and now know what it is. These shovels are not particularly expensive, e.g. Amazon Spear & Jackson for £26.40 delivered free. So could I achieve, say, 3ft depth with one? Are they hard graft? I'm getting on in years and had a heart op 18 months ago. Feeling as fit as a fiddle now, but... A post shovel looks like hard work!

MM

[MM]

The spike on these doesn't look very long, will it work? (I suppose it must, otherwise they wouldn't sell any.) How much effort to bang 'em in? I do have a sledge hammer.

(I'm a bit dubious about banging things blind into the ground willy nilly, as I might I hit a pipe.)

MM

[MM]

Tell me more, Scott, about these repair spurs? Are they specifically/only meant for fixing broken posts?

By the way, suppose I find, on close inspection around the base of the existing post, that it's NOT rotten, couldn't I just whack a load of that postcrete stuff down and around it, while supporting the fence for 48 hours with a couple of struts?

MM

[MM]

I've googled it now! Cool tool, and not expensive.

MM

[Chris Hogg]

I used a garden hand-trowel to loosen the earth, an empty baked-bean can to scoop it up, and a long arm to reach down, lying full length on the ground, to excavate my post-holes.

[Chris Hogg]

I guess their life depends on where you live. I've seen 'Metpost' type things rust away in a very few years. We live by the sea and there's a lot of salt in the air blown in on the winter gales. Get galvanised ones, at least, but I have little faith in galvanised anything these days; the galvanising is never thick enough. My wooden posts set in Postmix have lasted twelve years so far with no sign of rotting, but as Harry suggests, I think I'd go for concrete stubs set in concrete and bolt the wooden posts to them, next time, or even whole concrete posts.

[MM]

Or what about a Draper 24414 1050mm Fence Post Auger? On Amazon for £21.24 with lots of positive reviews.

MM

[Tim Watts]

There are several forms:

Long handle (1.5-2m or so) with a very small square shovel head, not much bigger than a trowel.

Double type with scissor action:

You'll generally need a 4'-6' iron breaker bar to loosen the bottom of the hole and dislodge rocks.

You can manage without all these things (although the iron bar is useful) but it will take longer and you may end up with a bigger hole and thus more concrete.

[Tim Watts]

You could hire a petrol driven post auger.

These vary from a manual type - easier if you and a mate hold each side, both for lifting it and to counteract torque.

The bigger type are on wheels and should make the job very easy.

[Tim Watts]

The other option is 2" thick angle iron. Set in concrete, leaving 18-24" above ground.

Fix post to it with coach screws through both faces.