In article ,
stuart noble wrote:

I have some tanalised posts that I put in 25-30 years ago, and
are still solid.

IME they rot at ground level because of prolonged contact with water,
but you can reduce the chances of that happening by having a concrete
base visible above ground and keeping the bases clear of vegetation.

Mine are directly in the ground, because using concrete means that
you can't plant climbers ar their base. But, yes, using a concrete
collar (it doesn't need to go down below 6-9") does help protect
weakly treated posts.


Regards,
Nick Maclaren.

stuart noble wrote:

IME they rot at ground level because of prolonged contact with water,
but you can reduce the chances of that happening by having a concrete
base visible above ground and keeping the bases clear of vegetation.

I was considering resting the corners on 1/4 paving slab "pads" to deter
them from settling into the soil and shifting around, as mentioned
earlier I am considering lining them, weed membrane would be porous, so
would have to be a full waterproof membrane to stop soil within the beds
rotting them from inside out, rather than from ground-level up

On 06/03/2014 09:44, Nick Maclaren wrote:
In article ,
stuart noble wrote:

I have some tanalised posts that I put in 25-30 years ago, and
are still solid.

IME they rot at ground level because of prolonged contact with water,
but you can reduce the chances of that happening by having a concrete
base visible above ground and keeping the bases clear of vegetation.

Mine are directly in the ground, because using concrete means that
you can't plant climbers ar their base. But, yes, using a concrete
collar (it doesn't need to go down below 6-9") does help protect
weakly treated posts.


Regards,
Nick Maclaren.


That's pretty amazing

On 06/03/2014 13:40, Andy Burns wrote:
stuart noble wrote:

IME they rot at ground level because of prolonged contact with water,
but you can reduce the chances of that happening by having a concrete
base visible above ground and keeping the bases clear of vegetation.

I was considering resting the corners on 1/4 paving slab "pads" to deter
them from settling into the soil and shifting around, as mentioned
earlier I am considering lining them, weed membrane would be porous, so
would have to be a full waterproof membrane to stop soil within the beds
rotting them from inside out, rather than from ground-level up


Why not use paving slabs or half slabs on edge to make the beds, they
will never rot

On 06/03/2014 14:12, David Hill wrote:
On 06/03/2014 13:40, Andy Burns wrote:
stuart noble wrote:

IME they rot at ground level because of prolonged contact with water,
but you can reduce the chances of that happening by having a concrete
base visible above ground and keeping the bases clear of vegetation.

I was considering resting the corners on 1/4 paving slab "pads" to deter
them from settling into the soil and shifting around, as mentioned
earlier I am considering lining them, weed membrane would be porous, so
would have to be a full waterproof membrane to stop soil within the beds
rotting them from inside out, rather than from ground-level up


Why not use paving slabs or half slabs on edge to make the beds, they
will never rot
OR a run of concrete blocks

David Hill wrote:

Why not use paving slabs or half slabs on edge to make the beds, they
will never rot

True, but partly for appearance, and partly because anything involving
conceting things into place takes me forever and does my back in - taken
me long enough to set round topped kerbing round two edges of the
garden, perhaps overkill, but they'll never move and end-up looking all
straggly toothed like the bricks set on edge I inherited.

Armed with an impact driver and circular saw, I can knock up the beds
pretty quickly I reckon ...

On 06/03/2014 14:14, David Hill wrote:
On 06/03/2014 14:12, David Hill wrote:
On 06/03/2014 13:40, Andy Burns wrote:
stuart noble wrote:

IME they rot at ground level because of prolonged contact with water,
but you can reduce the chances of that happening by having a concrete
base visible above ground and keeping the bases clear of vegetation.

I was considering resting the corners on 1/4 paving slab "pads" to deter
them from settling into the soil and shifting around, as mentioned
earlier I am considering lining them, weed membrane would be porous, so
would have to be a full waterproof membrane to stop soil within the beds
rotting them from inside out, rather than from ground-level up


Why not use paving slabs or half slabs on edge to make the beds, they
will never rot
OR a run of concrete blocks

Bricks look better but the old ones are over a quid each in South East.

The membrane thing doesn't work IME. The inner surface of the wood will
always be wet because there is no airflow to allow it to dry.

On Wednesday, March 5, 2014 7:06:20 PM UTC, Dave Hill wrote:
On 05/03/2014 18:54, stuart noble wrote:

On 05/03/2014 16:01, Andy Burns wrote:

Pete C wrote:



On 05/03/2014 13:08, Nick Maclaren wrote:



Pete C wrote:



Oak will outlive treated softwood by decades.



Sorry, but that is so misleading as to be false.



Oak heartwood will outlast cheaply treated softwood by decades,

true, but oak sapwood will not last that long, and the most

aggressively treated softwoods (the old pressure-creosoted and

tanalised ones) will outlast oak heartwood by decades. What am

an not sure is how effective the tanalisation replacement is.



Sorry Nick, I was only repeating what I've seen on television.



Thanks all, the spec of the oak sleepers allows a maximum of one waney

edge, so could be sapwood, but I prefer the look of oak, will likely go

for it.





In direct contact with soil nothing's going to last that long





Off topic a little.

In much of West Wales the veg gardens are made up into beds by taking

the top soil from the paths and using it to raise the bed height, so

often the beds are 12 inches or more above the path height, this gives

drainage and at no cost .

David @ a rain-free side of Swansea Bay

Yes, that's how I made my 'raised' beds. It's especially useful if your topsoil isn't as deep as you'd like. A certain amount of maintenance is required to keep the soil where you want it.
If the op want's to use oak and can afford it - what's not to like?
I also did several beds like this using larch about 8 years ago and they're still in use by my successors. It's worth taking some time in preparation. Digging the bottom of the intended bed, adding organic stuff, then piling the soil from the paths onto the bed and then installing the boards. If he hasn't got a good cordless drill/driver this is a good excuse to get one.
Rod

On Thu, 06 Mar 2014 14:09:00 +0000, stuart noble wrote:

On 06/03/2014 09:44, Nick Maclaren wrote:
In article ,
stuart noble wrote:


Mine are directly in the ground, because using concrete means that you
can't plant climbers ar their base. But, yes, using a concrete collar
(it doesn't need to go down below 6-9") does help protect weakly
treated posts.


That's pretty amazing


I also have pressure treated pine half-rounds directly in the soil, no
sign of rot after more than 20 years. And also put climbers on the
fencing where there's enough light. Believe me, the ground gets pretty
wet, too! :/ Oddly the rails seem much more inclined to rot than the
posts.


--
Gardening in Lower Normandy

On Thu, 06 Mar 2014 14:49:54 +0000, Andy Burns wrote:

David Hill wrote:

Why not use paving slabs or half slabs on edge to make the beds, they
will never rot

True, but partly for appearance, and partly because anything involving
conceting things into place takes me forever and does my back in - taken
me long enough to set round topped kerbing round two edges of the
garden, perhaps overkill, but they'll never move and end-up looking all
straggly toothed like the bricks set on edge I inherited.


Around here the farmers use chestnut or acacia for fence posts, because
it doesn't rot (well OK, it rots slowly and bugs don't like it). I know
this is widely practised in some places, e.g:

http://www.dorsetfencingsupplies.co....t_fencing.html

If I could find machined logs, I'd build it with that rather than the
oak. Probably less dear too.

-E

--
Gardening in Lower Normandy

In article ,
Emery Davis wrote:

Around here the farmers use chestnut or acacia for fence posts, because
it doesn't rot (well OK, it rots slowly and bugs don't like it). I know
this is widely practised in some places, e.g:

http://www.dorsetfencingsupplies.co....t_fencing.html

We initially used chestnut poles, as used in hop gardens, and
they lasted only 3-4 years before rotting through. I am not sure
why they were so much less durable here than in Kent, but suspect
that real hop gardens used pressure treated poles, and not dipped
ones.


Regards,
Nick Maclaren.

On Wed, 5 Mar 2014 15:28:53 -0000, "Bob Hobden"
wrote:


My interest is why you need raised beds? Terrible waste of ground with all
the paths so you need a good reason to want them.

So you can go pick your strawberries in your slippers :-)

As for building them, I use 'decking' It been down now four five years
and looks as good as ever .

"Derek" wrote ...

"Bob Hobden" wrote:


My interest is why you need raised beds? Terrible waste of ground with all
the paths so you need a good reason to want them.

So you can go pick your strawberries in your slippers :-)

As for building them, I use 'decking' It been down now four five years
and looks as good as ever .


Unless you have a serious problem with your soil for what you want to grow
or need to improve drainage I don't see any advantage. Just more work, more
expense, and less ground to cultivate.
--
Regards. Bob Hobden.
Posted to this Newsgroup from the W of London, UK

On Thu, 06 Mar 2014 17:24:01 +0000, Nick Maclaren wrote:

We initially used chestnut poles, as used in hop gardens, and they
lasted only 3-4 years before rotting through. I am not sure why they
were so much less durable here than in Kent, but suspect that real hop
gardens used pressure treated poles, and not dipped ones.

Interesting, those I've seen aren't treated at all. Even the thin posts
seem to last really well, we've got tons of old barbed wired on it, the
posts are still mostly reasonably sound after God knows how many years...

--
Gardening in Lower Normandy

On 06/03/2014 18:30, Emery Davis wrote:
On Thu, 06 Mar 2014 17:24:01 +0000, Nick Maclaren wrote:

We initially used chestnut poles, as used in hop gardens, and they
lasted only 3-4 years before rotting through. I am not sure why they
were so much less durable here than in Kent, but suspect that real hop
gardens used pressure treated poles, and not dipped ones.

Interesting, those I've seen aren't treated at all. Even the thin posts
seem to last really well, we've got tons of old barbed wired on it, the
posts are still mostly reasonably sound after God knows how many years...

In the dim and distant past when I lived outside Hastings we used
chestnut stakes and posts they were normally used untreated though a few
did have a 5 minute dip in creosote, they lasted indefinitely, certainly
over 10 years.
Our only complaint was that if you used old chestnut on an open fire the
wood spat like crazy and ruined a few rugs of ours.
David @ the side of Swansea bay where we have had fog and rain all day.