Durable wood in ground ?

[zak99]

I want to make a big arty farty post thats fixed in the ground for a garden project. What are best options for durable timber please? (Possibly waney edge)

 

[Cobbs]

I want to make a big arty farty post thats fixed in the ground for a garden project. What are best options for durable timber please? (Possibly waney edge)

Oak or Sweet Chestnut, but don't use waney edge as the sapwood will rot first and fast.

 

[Fitzroy]

How durable will be the question. Larch for example will give you 10yrs, is that long enough?

• Larch is in the durability class of 3 – 4. Durability is the measurement of a 50mm x 50mm cross section of timber left in the ground unprotected. Class 3 is 10 – 15 years. Class 4 is 5 – 10 years. When untreated and NOT in ground contact you can expect a life of 50 – 60 years. When treated and outdoors the life expectancy is 100 years.

As per Cobbs, our two most easily accessible class 2 timbers are Oak and Sweet Chestnut, and pretty much the only class one timber you'll get hold of in big sections in the uk is Greenheart.

I think this is a good resource, except that the graphic is upsetting in it's random placing of classes.
https://www.thewilddeckcompany.co.uk/about/timber-durability-classes/

Fitz

 

[dzj]

Black Locust, if you can find it.

 

[zak99]

Thank you that’s really helpful. I’m guessing sweet chestnut heartwood is not easily found in large sections?

Off topic - I have some thin chestnut planks in the garage (under weights) a friend gave me but apparently it’s a mix of sweet and horse and he said horse was not as durable, will be fun distinguishing which is which.

Ruling out waney edge for early rot reasons perhaps leads me to a possible alternative of faking weathered driftwood, need to research if that’s feasible.

 

[niall Y]

There is a BS test for timber rather colourfully called " The graveyard test" where samples are partly buried in the ground.
From personal experience, with treated posts, I also coat the base with bitumen to several inches above ground level. Just to be sure.

 

[alex robinson]

Thank you that’s really helpful. I’m guessing sweet chestnut heartwood is not easily found in large sections?

Off topic - I have some thin chestnut planks in the garage (under weights) a friend gave me but apparently it’s a mix of sweet and horse and he said horse was not as durable, will be fun distinguishing which is which.

Ruling out waney edge for early rot reasons perhaps leads me to a possible alternative of faking weathered driftwood, need to research if that’s feasible.

Distinguishing the two should be fairly easy. Sweet chestnut is ring porous whereas horse chestnut is diffuse porous. Sweet chestnut is also a brown colour similar to oak and horse chestnut is a more pale creamy colour.

 

[Phil Pascoe]

You don't say where you are.
https://www.uk-timber.co.uk/new-unt...ew-azobe-ekki-untreated-railway-sleepers.html

 

[zak99]

You don't say where you are.
https://www.uk-timber.co.uk/new-unt...ew-azobe-ekki-untreated-railway-sleepers.html

Thanks Phil, I’m in Essex a long way from Corby unfortunately

 

[Chubber]

Elm? Roman elm water pipes have been unearthed in remarkable condition.

 

[Phil Pascoe]

It doesn't work well when one part is above ground, it works only when permanently wet. It'll rot at ground level.

 

[Chubber]

Thanks, Phil, for me every day's a school day, I didn't know that. My wife daily reads out odd things from the papers at breakfast time, helps sometimes with quizzes and crosswords.

This mornings offering.?

Lesotho is the only only country in the world which is wholly over 1000 metres above sea-level......