Untreated larch fenceposts?

[LichenFarmer]

I just wonder how long people think untreated fenceposts made of larch would last. Obviously there are many factors and there will be a big range, but I've got no idea really -- I know larch is considered a durable timber for exterior use, but then the demands on a post in the ground are much higher than for cladding a building.

If it was made entirely of larch heartwood how do we think it might compare with a treated spruce pole? Or an untreated chestnut one?

Cheers Joe

 

[William G]

I just wonder how long people think untreated fenceposts made of larch would last. Obviously there are many factors and there will be a big range, but I've got no idea really -- I know larch is considered a durable timber for exterior use, but then the demands on a post in the ground are much higher than for cladding a building.

If it was made entirely of larch heartwood how do we think it might compare with a treated spruce pole? Or an untreated chestnut one?

Cheers Joe

Did a fence on a housing development around 10 years ago. 100mm x 100mm posts. Untreated heartwood larch concreted in as specified by architects. Thought they were mad and voiced my concerns. But fair play there all still standing. Had treated strainer posts not concreted in fail since then. Possibly heartwood only is answer as treatment certainly isn’t

 

[berisford]

Got over 100 year old European larch trees here,most are no thicker than an electric pole,even the fence posts from them only last under 10 years,they seem to go brittle and snap off,could never get creosote to penetrate them.

 

[LichenFarmer]

But fair play there all still standing.

Impressive. Though I guess they won't be subject up the same moisture levels as just banged in the ground.

 

[LichenFarmer]

Got over 100 year old European larch trees here,most are no thicker than an electric pole,even the fence posts from them only last under 10 years,they seem to go brittle and snap off,could never get creosote to penetrate them.

Wow. Slow grown timber is supposed to be strong. (That's one of the selling points for Octoposts) How come it has grown so slowly?

 

[egbert]

I just wonder how long people think untreated fenceposts made of larch would last. Obviously there are many factors and there will be a big range, but I've got no idea really -- I know larch is considered a durable timber for exterior use, but then the demands on a post in the ground are much higher than for cladding a building.

If it was made entirely of larch heartwood how do we think it might compare with a treated spruce pole? Or an untreated chestnut one?

Cheers Joe

There's larch and there's larch.

European larch (eurolepis) was brought here hundreds of years ago.
Japanese larch much later, and their hybrid appeared later again.

The euro is generally much more durable - heartwood that is.
Jap/hybrid grows faster, which need not make any difference to strength...but it is not as durable.

Euro was superseded in most plantings about a century ago, so mature euro is hard to find now.
Conversely it isn't much affected by phytophra (spelling?), so on virgin sites, i still plant a bit of it now.

Euro can be very 'greasy', full of resin. This is a bitch in the sawmill, but this is the most durable.
I've an untreated sq sawn post hanging a gate in the yard after 15 plus years.
(can't explain @beresford 's brittle larch problem?????)

Like for like, most larch heartwood is going to be barely more durable than inadequately spruce. (there's a lot of variation in quality of treatment)

I wouldn't use anything but the greasiest euro in ground contact for choice, and would treat anyway unless it was clearly all heartwood, and i was in a hurry!
(and there was no creo posts in the heap)
I never use tanalised now...end of

 

[William G]

Impressive. Though I guess they won't be subject up the same moisture levels as just banged in the ground.

Concreted in posts are generally more prone to rot than driven in posts.

 

[Islandcrofter]

Done a fence in 01 was giving larch posts by mistake they are still still perfect . Needed more posts to finish of the job was giving treated post which need replacing now.

 

[LichenFarmer]

Wow... And these are completely untreated, aye?
That's excellent.

 

[Islandcrofter]

Untreated . Needed more posts lorry came with them they was a colour difference . Driver phoned office and said the larch were a special order for some and got them by mistake. Glad i didn't have to pay the extra as was told there was a big price difference..

 

[tepapa]

Like for like, most larch heartwood is going to be barely more durable than inadequately spruce. (there's a lot of variation in quality of treatment)

You've lost me there Egbert heartwood is no better than spruce? Is it the softwood or heartwood that's least prone to rot?

On a separate note. Whats the value of European larch in lengths collected from the forest . I pressume it's sold by the ton?

 

[egbert]

You've lost me there Egbert heartwood is no better than spruce? Is it the softwood or heartwood that's least prone to rot?

On a separate note. Whats the value of European larch in lengths collected from the forest . I pressume it's sold by the ton?

think i might've lost me'self!

Think I was saying that jap/hybrid larch heartwood* mightn't be better untreated than treated spruce (if the treatment is done right...which isn't a given)
*Sapwood of either/any isn't durable without treatment.
It's a very moveable feast though.
Some is better than others, while I believe some spruce is much more resilient to taking treatment than others.

We were milling jap larch today, 3 logs from the same stand..... and 2 had a feeling of the heart being pretty good - a greasy feel to it/evident resin, while the very fast growth in the middle of the 3rd and biggest didn't feel as clever. Nearly spongy, and dry to handle.
it won't matter in the roof it's going in...but untreated in ground contact, there would a significant variation.

Eurolepis (if you have got a line on some)....
sawlogs of any quality - and any larch species- would be (in the westcountry) circa £100/tonne roadside...the market is on fire.
Big clean euro larch sawlogs? Depend on who was chasing, but I wouldn't be surprised if the right gear was £150/T

Fencing sizes?
I'm not sure, but you'd be up against the pulp/chip price putting a strong floor in it, and the cutters not wanting to dick about cutting fence spec lengths.

I can find out if you want

 

[Farm buy]

I just wonder how long people think untreated fenceposts made of larch would last. Obviously there are many factors and there will be a big range, but I've got no idea really -- I know larch is considered a durable timber for exterior use, but then the demands on a post in the ground are much higher than for cladding a building.

If it was made entirely of larch heartwood how do we think it might compare with a treated spruce pole? Or an untreated chestnut one?

Cheers Joe

I did deer fencing 30 years ago, Sika spruce dried in front of the sawmills generator in a small family run outfit in . Pressure treated with then ,all post were there perfect 10years ago , about half of them there now.
I am completely convinced that the timber drying is the secret to treating timber. Treatment cannot go into the timber unless the moisture is taken out.I paid 50 pence/post more to that man to dry the post. Best money ever spent. Bought a small number of untreated european larch for a small field extension. They did not last much more than 5 or 6 yrs.

 

[tepapa]

I did deer fencing 30 years ago, Sika spruce dried in front of the sawmills generator in a small family run outfit in . Pressure treated with then ,all post were there perfect 10years ago , about half of them there now.
I am completely convinced that the timber drying is the secret to treating timber. Treatment cannot go into the timber unless the moisture is taken out.I paid 50 pence/post more to that man to dry the post. Best money ever spent. Bought a small number of untreated european larch for a small field extension. They did not last much more than 5 or 6 yrs.

Posts treated 30 years ago will have been done with CCA and it just shows how good the chemical was at preserving timber. No matter how dry you get posts nowadays tanalith won't even do a third of that.

 

[Farm buy]

Posts treated 30 years ago will have been done with CCA and it just shows how good the chemical was at preserving timber. No matter how dry you get posts nowadays tanalith won't even do a third of that.

Something bad wrong now as we are not getting any life on the cattle paddocks post now days

 

[tepapa]

Something bad wrong now as we are not getting any life on the cattle paddocks post now days

They're solely relying on copper as the preserving chemical when in fact it was the arsenic and chromium that where doing the work in CCA but we can thank the EU for banning them.

 

[TripleSix]

We've made some of our own from euro larch over the past couple of years, some as rounds, some split on the sawbench.

They're certainly very hard.
They can't be any worse than modern round posts, we've had some rot from the top within 3 years!

 

[Bury the Trash]

Posts treated 30 years ago will have been done with CCA and it just shows how good the chemical was at preserving timber. No matter how dry you get posts nowadays tanalith won't even do a third of that.

even with cca they still had to be dry and well pressure treated to last , there was still some batches that didn't last particularly long because sawmills were pushing them out too fast, that was apparent as it got closer and closer to being banned ,bit of panic i suppose.