MYTHBUSTED: “Cement will Rot Posts. Even Pressure Treated.”

This Pressure Treated 4x4 was 15 years old and it’s still solid and strong as a $2 steak. Yes, you can set fence posts directly into cement.

#fence #fencecompany #fencebuilding #construction #diy #carpentry #fencecontractor #mythbusters #mythbusted #4x4 #renovation #remodel
#building #builder #outdoors #oregon #portland #concrete #lumber #pressuretreated #wood #handyman #handymantips

[leifwirtanen]

The new pressure treated posts have much less chemicals so they rot out quicker. Rot also needs oxygen to start, so you wont see rot on the bottom. It will always rot within 6” of the ground surface.

[tomlawless]

Why is the world still so confused on how to put a bloody stick in the

[IRJU_GREYMAN]

It needs to be fully encapsulated in concrete everyone does the same thing drop the post in the hole then add crete. Add crete to the bottom of the hole(2") then post, then crete again and tamp. Crete slightly above ground angled to drain

[bolodogrc]

It does help to slope the top of Crete not hold as much standing water . I've had one rot in 8 years cuz of standing water on it .. but I changed it and was sure to slope it and it didn't rot and ground level

[LaFox]

Depends on how much rain exposure it gets. I have a fence line under tree canopies with 4x4 pressure treated posts set into concrete. Hasn’t rotted out and is still going strong for over a decade. However I also have a fence line completely exposed. Rotted right through actual 4x4s and 4x8s. If you’re worried about rot you’re better off using metal posts.

[_kainzow]

The reason most people's fence posts rot is because they set the concrete below ground level. So dirt gets up next to the post and slowly rots it away. That's why anyone good fencer will dome the top of the concrete to avoid this.

[MrNside]

So this one post by -random youtuber- negates all of the rotten posts I've removed/replaced over the decades...

[happyman]

The crete will seal the wood. The exposed top will wick out moisture. Direct burial or using gravel will rot one out much quicker because of always being wet.

[GeorgePollinger]

Concrete absorbs water. Ergo, the post will rot. I've tried foundation coating and it helped a bit. Apparently, the best solution is to scortch/charr the burried portion of a post 2-3" above ground. I did that 2 years ago and it's supposed to prevent rotting for decades.

[Kurdain]

Father has 11 buildings on his property, all built himself, largest being 109x36 feet. All use support posts of various sizes, none pressure treated, just the part in the ground soaked in 50/50 old oil + diesel. Most were built while I was a child, I am now nearly 50 years old, none have rotted despite them being set in concrete.
To be fair nearly all are not open and exposed like this being building supports, but even the open-faced lean-to style shop hasn't rotted and it's as old as I am.

[davidrick]

Supposed to bell shape bottom of the hole to prevent the post from heaving out of ground from freezing.

[LujinCustom]

We coat the below ground part of the post with creosote.

[Beauvincelli]

You’re tapping the wrong spot. It’s where the wood connects to the concrete at the top of the concrete because that’s where the water sits.

[hugh]

My 10 yr old concrete fixed posts broke at the ground line not at the bottom. I won't use concrete again

[clarenceking]

What are you gonna set it in instead????

[inrtuning]

Everything in Portland is rotten... right down to this guy's fence posts.

[elvinebovine]

Root is microbial. Wood doesn’t just rot on its own. Kill the microbes feeding on the post and it will not rot… simple. Mycorrhizal fungi is great for gardens but bad for posts. If a post rots, you’ll want to replace the surrounding soil where the rot occurred. Salt and anti microbial soap treatments work well.

[brflr]

Every Post has its day; if a new Post is needed then a good Man would replace it all in one days work. Leave that bickering for the Ladies.

[netterjeff]

That post looks new. Couldn’t have been in the ground more than a couple years.

[RileyNewcomb]

Looks like whoever set that post needs to pull up a hair to get the cement underneath