Dry concrete mix in a post hole?

I've never done it...always mixed with water. Has anybody had good luck just dumping the dry mix in the hole around the post?

Placing concrete around a wooden post causes it to rot.

I have "dry bagged" deck posts many times. As far as I can tell, it works fine. I'm interested what others say.......

......but I always had a good bit of gravel on the bottom of the hole.

Same as above and never had a problem.

We always dump little water in hole first, couple gallons, dump dry concrete in then gallon or 2 on top. Big pours we get concrete truck. But probably several hundred with dry bags. As stated I won't do it with wood post, pipe only. Wood rots inside concrete and leaves a gap fir moisture and that speeds up the rotting process. Good hedge post lasts longer with no cement.

I know pole barn builders that tamp dry mix around the poles they put in the ground. I have never seen or heard of issues doing that.

What Yes Sir said

I would mix it first. That way you know it was mixed completely threw! No dry spots!

Rot with treated 4x4???

I saw a pill box on Adak made out of bags of cement stacked There was a I beam down the center and bags on top. The shooting ports were from ground level up about 4-6 inches. You went down steps and around a corner to get in. It would have been made in the 1940's and was still there.

I don't know what your building but when we build fence we want it to last at least 2 or 3 generations. If a good hedge post will rot in concrete I promise a treated 4×4 doesn't stand a chance.

If you’re going to use concrete, it goes in the bottom of the hole well below the frost line. It acts like a pad and the post sits on top. Wrap the post loosely with tar paper so frost doesn’t grab it.

Hmmm. It's a landing/small deck out a door.

After I retired from grazing cattle, I removed all my high tensile wire, steel T posts and pressure treated wood fence posts. Regarding rot to posts, 90% of the rot occurs in the top 8 - 10" of soil.
About halfway through building my fences, I began backfilling and packing the posts with limestone gravel. Years later many of them hardly showed any sign of being in the ground at all.
If nothing else, pre-treat the post with a decent oil based stain, just the 12" that will be from the soil surface and down.

I understand. When I read post, fence post is my first line of thinking

I own a pole building company and have seen it done many different ways. I pretty much agree with what the others said. We mix with water in an electric concrete mixer and pour it in the hole. It won’t pass inspection otherwise. Never concrete around the post.

Phil Brown knows concrete. Phil, what say you?

A couple concrete guys always said to mix properly before dumping in holes. Some farmers I know use dry bagged right down the hole.

https://www.quikrete.com/athome/settingposts.asp

The manufacturer of the concrete says that's the way to do it.

I would tar the post up to the expected dirt level. An a wrap of plastic wouldn’t hurt after you tar it. But yes concrete will eat up a wood post treated or not. Also have noticed a difference in a post that just had the bag dumped around it vs one that had mixed cement around it. Seemed like the dumped bag never cured. But the mixed bags did. Kinda like the cement on the outside absorbed the moister an hardened a the inside wasn’t able to get enough moisture to set up a cure. Just the two cents from this concrete guy

Don't know if it is right or wrong but we have done a lot of pipe posts that way and they are still like we put them

I have a 6" 3/8" wall gate post that has 12 or so 80# bags of dry sackrete around it. I am confident that it will never lean or be pulled up with anything short of a D9

Just wet the hole first, then dump in mix,works great!

Always just dry and never had a problem

Hey Gary when I built my deck our support posts actually have an aluminum base that bolts to top of the flush filled footing. The base has a 1” air space designed right into the structure to keep the treated post dry, and NOT touching the concrete. It is designed to anchor the post but prevent rot…and yes treated lumber will eventually rot. Sent away a whole pile of the old deck, all treated, some rotted.
New bases, bolt to concrete footing, slide in the post, use deck nails to secure the post to the anchor. The 1” airspace between wood post (treated) and the concrete is to promote air flow and keep the wood dry.
Doesn’t matter if it’s treated it will rot if exposed to moisture and not allowed to dry out.
That was code here.
And I have no intention of redoing this deck for a LONG time.

Concrete in a post hole for a wood post should be used as a pad only. Dirt tamped solid for backfill. Concrete around a wood post will speed rot. Been doing it that way for many, many years.

Dry concrete in post holes for metal posts is fine and seems to be a very popular method with fence companies.

Over the past ten years or so I have been using the Simpson Stand Off's similar to what janNE shows above. I dig the holes, stick in a SonaTube so it's a bit above grade and sink an anchor bolt. After the concrete cures the Stand Off's get attached.

The Simpson Stand Off's, the heavily galvanized ones, are spendy but, IMO, well worth the money, no wood in contact with the ground.

I put up a few farm gates in with 6" steel posts- I added this mix dry and then added water onto as I went- turned out rock soild.

I like that idea. I'm in Arkansas where there's more rock than dirt and I'm not excited about digging deep holes, especially if the posts are gonna rot.

I’ve owned and operated a fence installation business for 32 years and I will never set a wood post in the ground. All our wood fences are built with metal posts set in concrete. I know this for a deck but same principle

My short stint with pole barn builder back in late 1970s. All the large barn post where set in hole on 6 inch thick concrete pad. Then we tamped in the lime rock gravel in around them gets almost like cement. I'm guessing it Is same rock TraderVic used.. I don't know what those post look like up close now. But those building are still standing.

Mac

Interesting that there is no consensus on the right way to do this.

I think we've established that concreting wood posts into the ground is bad, setting them on concrete pads and back-filling with dirt or gravel is better and not putting them in ground contact by using concrete pillars and stand off's is best.

If you put wood in ground just slather it up with creosote and provide crushed rock in the hole for drainage-last longer than you will.

If you completely submerge the bottom end of the post into the concrete, the concrete acts like a condom and will trap any water inside to accelerate the rotting process.

Glad I never used condoms.