6x6 treated posts in ground

[Spike56]

That's exactly what I was planning on using to build my pole barn - I have 5x5x10' non-treated poles that I was planning on using and, planning on dipping each post in roofing tar 6-12 inches above ground level.

Will it work (as far as reducing rot) ? I am in deep east texas, near the Toledo Bend dam, a few miles from the Louisiana border.

I have heard that dipping them in used motor oil works but have also heard that it is just a home remedy that doesn't work.

btw: Why am I using untreated? Because I can get these 5x5x10' poles from a local for $5 each. He can get me any size I want, but he doesn't have a way of treating them.

The *only* thing I would be concerned with about using Roofing Tar would be that it might develop cracks depending on how thick it is applied. If so, could water get to the wood and be held in ? I do not know.
Many people around here use 50-50 diesel / motor oil on their trailer boards. This seems to soak in rather than just cover. My 2 cents.... unsure. I put new boards on my trailer but used treated and a stain for treated lumber w/UV protection. Two years still like new.

 

[Rustyiron]

Have you ever trimmed a foot or so off of a pt 6x6?
The treatment isn't 1/3 of the way through it.
Short of concrete perma columns or one of those sleeve covers, I'd reccomend laminating (nailing/screwing) 3 2x6's together that are at least ground contact, or better direct burial rated. They seem to be able to get the "treatment" almost completely through 2x material.
Today's treatment is not equivalent to that of even 20 years ago!
Edit; I've also never had a "laminated" post that I've assembled or purchased complete twist and bow. Good luck with this using a 6x6.

 

[big bubba]

wouldn't be too concerned about rotting through...how old are you?

 

[pmmully]

Looking for opinions on the CCA treated posts .06 treated in the ground. My first was already built and the posts were already there. Had no problem other than had to put flashing between the treated band board and metal trim because rain would run under the trim and get between band board and enter building. Another company I checked out was about $7000 more to ad peirs under the posts. Seem a little high. I see pole barns all over and none are falling down. It is just me and putting wood in the ground. The place I would be getting the building built told me that I would not see a problem in my life time but maybe my kids grand kids might but then the building might have other issues because of age but posts are very good and bought for the purpose of pole barns. Also I would be adding gutters for extra protection.

It's all in the treatment. SYP#2 treated for direct burial is required. It's the same treatment for marine dock components that are direct burial and underwater rated.

 

[Sawyer Rob]

It's all in the treatment. SYP#2 treated for direct burial is required. It's the same treatment for marine dock components that are direct burial and underwater rated.

For marine rating, the post has to be treated to .80 or 1.0, barn poles are only rated .60, for in ground use.

SR

 

[rScotty]

For marine rating, the post has to be treated to .80 or 1.0, barn poles are only rated .60, for in ground use.

SR

Who do you order from so you can specify the treatment?
What is the cost difference?
Are there any other requirements?
How are telephone poles treated?

 

[Sawyer Rob]

Who do you order from so you can specify the treatment?
What is the cost difference?
Are there any other requirements?
How are telephone poles treated?

I order from a building supply house.
The difference in cost is drastic! .80 is a big jump and 1.0 is another big jump, all are spl. order.
Telephone poles have been treated several different ways, depending on how old they are and where you live.

SR

 

[CliffordK]

I'm surprised that so many people are building post in the ground pole barns, then often adding a concrete floor later. It would be just as easy to pour the concrete and add brackets for the poles.

However, it is quite possible that each part of the country has different requirements.

Around here, stuff in the ground rots. Cedar fence posts are good for 10, maybe 20 years. Pressure treated will last a little longer, but we've got a few PT posts reaching their end of life. And when my PT mailbox post fell over, there was nothing left under it.

A few years ago I built a lean-two connecting two sheds for a neighbor with a gravel floor. Keep the roof dry and the gravel floor will be OK, right? NOPE. Within a year I was also pouring a concrete floor due to too much moisture inside.

Yet, I could imagine sandy soils would be different. Keep the water away from the structure and the ground could be dry underneath.

Perhaps the anchoring of the posts to the ground impacts the survivability in a storm or natural disaster, yet, if the posts rot off to the point that they're only sitting on the ground, then one no longer has a strong anchor.

 

[masscity]

Nothing rots in the ground, only at ground level if you allow water to surround the post. My poles are 2x6 treated completely and 3 are nailed together to make a pole. I have the grade on PB where the water runs away from it.

I'm 77 and I won't live long enough to worry about it.

Edit: The rear part of the PB is on a hillside, it took 400 yards of compacted sand to bring it up to grade. My poles are in the ground a minimum of 51" in the front of the building, it's on a hillside and the lower ones are in 5' of sand and then 5' of clay.

 

[deezler]

I'm surprised that so many people are building post in the ground pole barns, then often adding a concrete floor later. It would be just as easy to pour the concrete and add brackets for the poles.

... You have to put your foundation down to or below the frost line. Here in Michigan that is 42" down south, and even deeper up north.

If you didn't have your structural posts down to frost line, you then need a complete concrete footing to frost line instead. Now you are adding five figures $$$ of concrete to your build.

My soil is sand and drains instantly. Yes, the posts are probably still damp underground. So what, they can slowly rot down there without affecting much of anything.

Personally, if I had a full concrete footing and slab installed first, then I would want to just stick frame the building walls, instead of using posts on brackets. A basic 2x6 stick frame wall isn't much more expensive than posts, headers, and 2x4 purlins, but then is soooo much easier to do insulation and electric within. Plus more robust for sheathing install. But the huge cost increase is the concrete footings.