My next door neighbor is getting a wood privacy fence (guess they do not like me sun bathing nude at my size and age - HaHa - that’s a joke) and I noticed this “professional” fence company they hired is digging the holes for the 4”x 4” wood posts and are setting them by leveling the pole in the hole, then a second guy is pouring a 50 or 60 lb bag of dry concrete into the hole distributing it on all four sides of the pole, tamping the dry concrete with a round broom handle sized pole, then filling the hole with water. That is all they are doing before moving to the next pole.

My question - Does this process allow for all of the concrete to receive the needed amount of water for the strongest setting or are these guys just short cutting the right way of pre-mixing the concrete mix before pouring into the hole.

I did the same 30 years ago when I did a fence in IA. About 4 years later straight line winds took out a section of the fence by snapping the posts off near ground level. The remaining posts/concrete anchors were a major PITA to get out and were one solid piece of concrete. So yes it works fine.

Two different pros did this on my fences.

There is a lot of moisture in the ground to add to the water dumped in.

first fence was done 2021 and the second was done two weeks ago.

Both have not moved.

It should be just fine. I helped my friend replace his dad’s fence a year out of HS. We didn’t use concrete at all we just used pea gravel. When I asked his dad if that was strong enough he said the one you just helped me take down was 25 years old and all pea gravel.

I did my fence 25 years ago with concrete but that’s only because I delivered concrete for a living and the boss let me take the truck with leftovers home to set my posts. If I ever have to set posts again it will probably just be pea gravel.

Thanks guys for your responses. Another lesson learned for me.

When growing up my dad always made us pre-mix our concrete for the small jobs around the house. This information will be passed to my two sons also because whenever we did anything requiring concrete we always pre-mixed.

Maybe overkill, but after multiple posts rotted at the base, I now put some mix in the hole first, then the post on top of that, then fill the rest of the hole, adding mix then water but by bit until the hole is full, trying not to get it too soupy.

I have found that not using concrete at all, just crusher run or other packable aggregate provides superior drainage and longer post life. Treated fence posts will last even when anchored with concrete, but untreated ones will rot far more quickly because the concrete tends to concentrate ground water around the post. Using concrete also makes the post much harder to replace when that becomes necessary as well as better maintaing plumb throughout its life. A concrete ball on the bottom of the post seems to act like a ball bearing in the soil and any frost heaving or other displacement shifts the post crookedly.

This is based on more than a decade of commercial fence installation. It wasn't unusual for a customer to insist on a concrete "footing." In those instances, dry packing did a better job of it than using a mix. One thing that even professionals often get wrong is using too much water in the mix. In truth, with ground water present, this is not easy to get right.

If you have to use wet concrete, use a very dry mix with lots of coarse aggregate and just a little cement.

Although the OP’s question is just pertaining to a fence post putting any structural post in the ground requires concrete, gravel won’t pass code.

The concrete should completely encompass the post including the bottom and should extend below the frost line. Of course, only ground contact approved CCA wood should be used.

Concrete will still be there long after the fence post has rot out. It's perfectly fine.

This is how I do mine. However I do put a layer of gravel at the bottom of the hole as a bit of a base.

I don't know I'm probably past 10K fence posts done that way. The weak point in all of it is not the concrete but the fact that we have screwed up PT treatment of posts. They all fail at the post

Concrete will always be stronger if properly mixed. But it will be perfectly acceptable to dry set post…

They have Post Hole Foam kits as well, been around for a bit so there is plenty of information, found a video where a guy does, Dry, Wet, Foam...

Did not know about the foam. Gonna have to read up on this.

Thanks HRK for posting this and to everyone who has provided comments and feedback.

Great video. Shows that the foam is a formidable opponent for sure. Years ago I built a pergola and used foam to set the four main posts. I didn't know at the time how good it was. Prior to that, I'd always premixed concrete and poured it in. Looks like that's preferable also.

Dry pour posts work, but like most things the devil is in the details. 3 key details from quikrete's own instructions:

overdig hole by 6" and put 6" crushed stone base

dump one 50-lb bag of fast setting concrete

dump 1-gallon of water per 50-lb bag

Some people live in areas with a frost zone deeper than 30" so the post needs to be below frost zone which necessitates knowing the additional detail from quikrete's fast setting concrete specification:

For holes deeper than 30 in (0.75 m), fill to a depth of 30 in (0.75 m) or less and wait until the water soaks all the way into the mix. Then add the remainder of the mix and water.

---

Ego is the anesthesia that deadens the pain of stupidity

DISCLAIMER: These are the author's own personal views and do not represent the views of the author's employer.