On Fri, 15 Jun 2018 08:35:27 +0100, Tim Lamb
wrote:

snip

It is possible to purchase fence posts pressure treated with creosote
from specialist suppliers.

Is it still 'creosote' (was it ever) when wood is 'Tanalised'?

This give a description of what looks like an 'extended' process (but
it might always have been like this):

http://tate-fencing.co.uk/about/tanalising-process/

I knew it generally use a lack of pressure (rather than 'pressure') to
draw the preservative into the timber but the above link takes it
further to potentially leave the surface of the timber 'drier'?

Seems there are quite a few different techniques ..

https://en.wikipedia.org/wiki/Wood_p...sure_processes

I have two 6" square gateposts and one has rotted off at ground level
and the other seems to be as good as new. I've got two steel posts
ready to go back in their place and the rest of the posts are
concrete. ;-)

Cheers, T i m