I'm in the process of taking down a hedge and putting up a new fence and I've found that in some areas, the ground is waterlogged to within a couple of inches of the surface.
The plan was for a ranch style fence with 4"x4" tanalised posts at 6' intervals and I'm wondering what's the best way to set the posts to give them the greatest longevity.
Given that they're bound to need replacing at some point, should I be thinking about making them *easy* to remove (by, i.e. setting them in gravel) or are there other things I should be considering.
How much work will the new labour intensive scheme involve over the next two centuries? How much wildlife will the new labour intensive scheme support over the next two centuries?
Who is going to get rid of the shit you install when you are poking out daisies?
What kind of longevity are you expecting in waterlogged ground? - I estimate
5 years maximum, and I don't believe the 'tannalised' part makes much difference - you may get up to 7 or 8 years, provided you soak the last 18 inches in creosote for a few days prior to planting - this isn't as hard or complicated as it sounds - you need a length of 100mm plastic pipe with a stop end, a plastic bag that fits inside it and a few gallon of creosote (creosote substitute now, but it's basically the same stuff). Fit bag inside pipe, stand in one post, fill to top with creosote and leave for 48 hours - if the stop end of the pipe is watertight you can do away with the bag.
Lean mix concrete might be better, IE 10 gravel, 6 sand, 1 cement - just something that won't wash away, but will be easily broken up when the need arises - it will also allow water through, which is important with wood - it's the cracks which appear in hard concrete around the base of the shrunken timber which hold water and cause end rot - soft, gravelly concrete eliminates this but still adds mass to the bottom of the post for stability, also, mix it completely dry - no water at all.
Hmm.., this was my "worse case scenario". I was hoping for nearer 10. I grant you 3x3 inch posts wouldn't last long but I was hopeful that 4x4 would do a bit better than that.
Thanks. I might well give the creosote a try (and your cement mix)
Lot of things with this particular hedge. Leylandii for a start, too high, too thick, wrong place.
Having hacked through the bl**dy thing I can assure you that there wasn't a single nest concealed within. It did seem to support the odd spider. I do plan to plant a new (much smaller hedge) but in the meantime, my neighbour and I want a new fence to mark the boundary.
What have you been smoking? Suggest you lay off the illicit substances before you next post.
Perhaps you should stick to shouting abuse at spammers (who I'm sure will listen to your every word).
At least Phil offers a sensible sollution to your dilema. However dont worry too much about making up a week concrete. It will resist water better if made stronger so you will get more time out of your fence. In addition bring the concrete slighly above ground level in a cone shape so that water runs off.
An alternative (so long as you or your neighbour isnt growing veg next to the fence) Is to soak the ends of the posts in used engine oil for a few days prior to putting them in. This greatly increases their life, and any garage will give you some for free. You can then take it to a car breaker, or back to the same garage for them to dispose of.
Good luck
Calum Sabey NewArk Traditional Kitchens 01556 690544
I built a carport recently. I read and was told that if you set a wooden post in concrete the worst rot will happen in the post just above the top of the concrete. Assuming that you do some decent concreting the section of the wood that will be stuck in the concrete will be quite protected and stay healthily moist and the worst rot will happen where the concrete ends and it isnt quite dry or wet. Additionally it rots worse if you do the concrete so it can puddle round the post. Looking at my wooden posts I can see where they change from wet to dry just above my concrete.
I set my posts by digging a hole and putting a 6 inch concrete base in it (normal wet mix even if it is underwater works fine). Leave that to set then drop the post onto it. Fill round the post with normal wet mix concrete and like Calum says bring the concrete up the post to above water level and slope it so the water runs off.
I also did this. Get buckets or whatever you can and leave the post standing in it for as long as possible. I only had a couple of days and a big post standing in around 2 inches of engine oil soaked it up to 4-6 inches.
Oh I know that. It's just that concrete posts are, IMO, as ugly as sin. It's a boundary fence between the front gardens of mine and my neighbours house so appearance matters. Metposts just seem like a way of guaranteeing that your posts are wobbly (& squint) for the whole of their life-time. I didn't mean to sound ungrateful for the suggestions.
The secret is to stop the bottoms of the posts absorbing water. Rather than just plonking the posts into their holes and pouring concrete around them, you should place a bit of slate or other impervious material at the bottom of the hole, so that the post is reasonably encapsulated from the soil.
I shouldn't worry too much about the existing water table. Make sure the ends of your posts are V well treated. Dig or bore your postholes to 2 feet. Set the posts in and fill the void. Tamp firmly. Don't use gravel or concrete, just soil to fill the void. Gravel will leave the post wobbly and concrete creates a moisture retaining necklace around the post. Decent posts should last about 20 years. Well bedded in soil it only takes a wiggle back/forth and left/right to uproot them. Alternatively, and this is a good time of year, try willow cuttings which could produce a 'living' fence. Good luck GS
So what u r saying is put them in a bucket of water ??
Concrete all around and at the bottom, so the posts will be resting in a pool of water all there life.
Its ground level down by 6 ins that always rots, its the water and microbes that do all the damage.
So you must get rid of
1 - Wood
2 - Water
3 - Microbes
Why not concrete godfathers and then wooden posts, I have these, and they have lasted 20 years. The wood is as good as 'new' and no sign of rotting. They have never been re-treated from new.
Is this water level just the normal winter water table and in summer it dries out.
No fencepost is going to sit securely in waterlogged soil.
You say Leylandii in a later post. They would not have survived sitting with their feet permanently in water. So where has the water suddenly come from? Is there a new source of water, (a leak or something?), or is it bad drainage, or what?
Maybe think about digging a trench parallel to the fenceline and draining the water to a sump.
The waterlogged part didn't have a hedge, it's at a low point in our neighbours front garden/drive and there's clay not too far beneath. There was a wobbly panel fence over the boggy stretch (vaguely secured with metposts).
How about putting the bottom of the post in a plastic bag? Something like a rubble sack, and taping it up, before pouring the concrete around it? In addition to engine oil/creosote?
The important thing is to pour the concrete so that it's slightly above ground level and flaunch it to slope slightly from the post so that water running down the post will tend to flow away.
Creosote is still a very good idea - soak the posts in it for a couple of days before use. Preferably real creosote, which is quite obtainable if you try ;-)
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