"Organic" fencing???

[TimberCutterDartmoor]

Larch, (as i'm sure you know) comes in 3 main types. Japanese is poor for durability, Hybrid a bit better but variable depending on how it grew, and European which is far superior but hard to get now. It's what we use for classic boat building, i.e ' larch on oak' build, and the species everyone refers to when they cite Larch as being a durable timber.

Oak is good if you just use the heartwood, but as you've already suggested, Sweet Chestnut (cleved, for the posts at least) would be my choice - strong, easy to work and more durable than the crap that passes for tanalised these days.

 

Larch on Oak - a few good memories there of boat building at Neilsons dry dock in Gloucester...

[David oakman]

You could try Alder for the posts find some nice straight coppiced Alder it will last for years in the ground i think as half of Venice is built on Alder. And split Larch oak or chestnut rails or if you know an overstood wood how about split 4 inch Hazel rails?

[sean]

All the London water companies between 16th and 18th centuries used elms for their pipes because of their resistance to decay when immersed in water.

 

In fact the Romans used elm too.

 

The job of boring all these pipes was arduous to say the least.....hence the term 'boring job'.....'i'm bored'!!!

[David oakman]

You are right Sean i forgot about Elm i have read that as well:thumbup:

[tommer9]

Elm will last for ever if permanently immersed, less if not, although it does last well. Oak and chestnut are both very very good, sweet chestnut being just about ahead in durability- whether in or out of the ground.

I have onely ever heard that Jap larch is very very very durable- it was once described to me as 'self tanalising' whatever that is supposesd to mean!! Suffice to say if the sap wood is removed it is extremely durable,. The reason the boat builders dont use it is the coarseness of grain making it unsuitable.

I think the soil association may have something to say about the tannins from green oak- not sure...

Alder is an excellent material for the job. It doesnt leach too much chemical and is eminently rot resistant.

Beech is totally out of the question as it rots quickly out of doors.

TBH i would go for sweet chestnut mate.

 

Stevie- when you say the 3" above and below ground for tanalised- well thats just the atrocious quality of modern day tanalizing. I am led to believe that the really nasty chemicals have been banned in favour of more eco friendly ones (WTF???) and the massive demand means that the pressure treatment is not getting in as far as it should. My mate who is a fencer says he has noticed the quality fall dramatically over the last 15 years, and it is not uncommon to have to replace rotten strainers after only a couple or three years, despite the promises made about longevity. I have seen 10" diametr tanalised posts with only an inch depth of tanalising and 3-4" stakes with clearly untreated middles too!!

If concrete is used around wooden posts (a massive no-no) this will cause premature rot at ground level too.

[Saw-sick Steve]

Oops, got me Larch round the wrong way, meant to have Hybrid as not very durable and Jap as better but variable. European would still be tops IMO. Boatbuilders do use Jap if they can't get Euro. Jap and hybrid are more resistant to canker if I remember correctly, so more widely planted now.

Alder is like Elm, good if immersed but not so good in that wet / dry zone. If it was, you'd see a lot more of it used for fencing down here - its one of the few things we can grow straight!

[samtheman365]

As a manager of a timber company (we have our own treatent plant) i can tell you that when they took all the nasty chemicals away from tanalised timber about 5 yrs ago, all we are getting now is customer complains with posts rottting after 3-4 yrs!!!

the british standard is 6mm of chemical penetration in timber

and if you see companies offering 15yr guarantee read the small print!!!!!

[digga]

i would go for sweet chestnut to as long as its cut when the saps down summer cut chestnut rots out in under half the time . alot of people seem to cut it in the summer which is a big no no in my book and part the reason why allot of people went off sweet chestnut for posts as they wasnt lasting but if done right they last just fine and if seasoned before putting in the ground they last even better

[Ian Leach]

Sweet chestnut all the way, was speaking to a bloke at the last show i was at and he said that his post have lasted 35 years. He just look them out of the ground cleaved them and put another fence back up.

[Andy Collins]

Ok everyone, thanks for the advice, have passed it onto the client, its up to him now!