Outdoor posts and Rot

[Munroast]

Going to be concreting some posts into the driveway

What I have are 8 foot long, square end tanalised 4x4s, but I am going to have to cut them down to 6'6".

So which end should I bung in the hole, then end that I have cut (and compromised the tanalising) or the good end?

I'm thinking as there is little rot 20" down that I should bury the cut end (rot seems to be most at ground level) The next bit of a post that is prone to rot is the very top where rainwater sits on it, hence have the good end there

Someone has told me I am doing it the wrong way - What do you all reckon?


I could soak the cut end in some old engine oil overnight, would it be worth the effort and mess?

 

[scbk]

It won't really matter, the main part of the post that rots is the few inches around ground level. If you want, you can cut the top of the post at a slight angle to shed water.


Soaking/painting the area that will end up at ground level with oil (or even better creosote) can only help. But the timber needs to be bone dry to start with so it soaks right in, then left to dry undercover for a good few days afterwards ideally

 

[foxhole]

You can cap the top to slow rot.

 

[Safety First]

I wouldn't worry about which end. I have never found either end of the post I am replacing as being as rotten as the part near the surface. Leave engine oil in your engine.

You need.....Postsavers!
I am not affiliated.
They work.
They are not cheap for what they are.
You can use bituminous flashing and blowtorch -melt the tar onto and into the wood if you are fast and adept at it. Wrap it in DPM and layers of more flashing.
Practice on some scraps.. I have done a few skinny 3 inch posts and they have survived 8 years and are rock hard under the DIY postsaver.
Postsavers and any diy alternative will look less pretty than bare wood but I have done more fencing than I would like and consistently witnessed the decay being mostly in the first 7 inches of soil. The principle of them is sound. The wood is destroyed by aerobic bacteria. Keep the bugs out of the wood in the depth/band where BOTH air and water are present and you will have no rot. I have dug out parts of posts from about 1 foot and deeper and found the wood saturated but almost entirely sound. I can recommend a post hole digger and cutting bar thing too.....if interested. Happy digging.