lifespan of a pressure treated 8x8 post

[GmGookieMonster]

Anyone know the lifespan of one which is out of the ground.

Thinking of using one to hold up a flat roof pergola, oak prices are just increasing all the time in my area

 

[bernardgreen]

One of 20 posts in a post and beam house. 8 x 2 Oregon Pine

These were pressure treated with Tanalith in 1980 and are still in very good condition. The lead under the post seals the end grain to prevent water getting into the inner grain.

 

[Notch7]

Anyone know the lifespan of one which is out of the ground.

Thinking of using one to hold up a flat roof pergola, oak prices are just increasing all the time in my area

Use a post saver....or use 300mm wide bitumen flash and use a heat gun and roller.
https://www.postsaver.com/

The key is to protect the section of post where it goes into the ground- that bit at top soil level is what rots.

Life span on an 8 x 8 post treated - probably 20 years and longer if above is done

 

[GmGookieMonster]

These will not be in the ground, they will sit on a 25mm thick post base

 

[^woody^]

The timber will outlast you. Except for the bottom 50mm or so that is constantly or mostly damp.

 

[GmGookieMonster]

Would green oak be a better option, its just the price here keeps rocketingcurrently i assume due to leaving eu.

I dont realy wanna replace summin in my lifettime if possible (38 currently by the way)

 

[bernardgreen]

A lot of information from TRADA

Includes timber merchant listings

 

[GmGookieMonster]

Ill have a look through though al of places dont even list what specie they have anyway

 

[^woody^]

Tanalith treated (green) will last the longest and can take prolonged dampness.

Other treated (normally brown) has less life and tends to require not permanently or prolonged damp.

The most important thing is to ensure that the ends (end grain) is suitably protected from constant damp - either via immersion or from water running down the post and soaking in the bottom

 

[Notch7]

These will not be in the ground, they will sit on a 25mm thick post base

it will last for decades, many

 

[jassdhali]

What about incised timber - life span ?
Possible option