mixing concrete

[Builder]

Most of the commercial fencing installation crews I've seen don't even bother pre-mixing/wetting it out...they set the posts with dry mix tamping it in then either soaking it or not even bothering allowing mother nature to finish the job...

Yep. That's the way the pole barns are built and fence posts are set, they just dump ready mix bags dry, right into the ground. The mix pulls moisture out of the soil and it drys like a rock. I've dug out so many posts done this way, and I can attest that it works.

There's 2 ways of looking at having concrete under load bearing posts. If they're pressure treated ground contact 6x6's, 6x4's, I auger my post holes, pour small 12" wide footings about 10-12" thick at the bottom, smooth the tops, let them dry, then stand the treated posts on the footing, then take a post spade and tamp backfill around the posts to slightly above ground level. This is more important if the building supports a larger load. It needs a wide base under it to keep the post from sinking itself into the ground. Concrete around the sides of the post can seperate and allow the post to sink if it's got enough load on it.

If you just put a post on dirt then put concrete around it, it's not a true concrete footing. Think about it-would you dig a trench and put concrete block on the dirt, then pour conrete next to the wall in the trench? Of course not, you first pour a continuous concrete footing, then put the block walls on top.

However, if we're talking untreated fence posts, it's not critical since it's a non-load bearing post.

The other thing to remember is that if it's a treated post and you cut the bottom, it is more succeptable to rotting. The tips should be put in the ground uncut-factory finish. Re-treat them if they are cut and placed undergound.

 

[rambler]

In my soils and climate, concrete is a bad thing on a wooden fence post. No noe does that a second time! Rots them out real fast.

The post will only rot in the 8-12 inch deep area where the moisture comes & goes. Below grade the wood will come out like new, and above ground it will be like new weathered wood. The rot zone is only a few inches just below the surface.

Some codes want a collar of concrete around pole barn poles to resist pulling out. Some want a pad under the poles to prevent sinking.

But no one likes pouring concrete around a wood post - at least not when they are rebuilding the rotted out fence the second time.

I realize different soils, different climates, things need to be done differently.

--->Paul