6x6 treated posts in ground

[mechanic]

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.

 

[s219]

If they are good quality and treated well, I wouldn't worry about it. You can avoid the most common issues by keeping roof rain runoff away from the base of the building (overhang and/or gutters) and grade the land away from the building.

 

[RNeumann]

In general, wood shouldn't contact the ground- houses and commercial buildings prove this. The question is, is it worth a few grand more to use the concrete piers or footings. I've seen pole bars with rotten posts after 10 years and others that are fine at 50+ years. It all depends on soil, moisture, bugs, treatment quality and post quality.

My opinion is a building is only as good as the foundation. It's not the place I'd try and save money.
But I don't buy cheap tools or drive on bald tires so maybe I'm the crazy one!

Ask the company that is telling you the posts will last generations to provide a written warranty. It would be interesting to see what the contractor and post manufacture actually would guarantee.

 

[bcp]

Recommendations for treatment levels are here:
CCAResearch.org - What is Treated Wood?

Bruce

 

[Shaneard]

How many mail box post you see in the ground made from 4" X 4" treated post? They are exposed to the elements for a very long time before you ever see failure. If you can keep the water away I wouldn't worry with it one bit on a 6" X 6". Concrete them in for even more protection. We use old power poles on all our sheds and never have an issue.

 

[bigdeano]

I've had pressure treated 4 x 4 fence posts rot off here in about 12 years, but it's very wet here. I think it helps a lot to use crushed rock for fill around the posts instead of dirt, but I don't have any numerical data. Maybe you can google some data on it.

 

[oosik]

My four stall carport has treated 4" x 4" posts with direct ground burial. That's 12 - 4x4's and for whatever reason, one of them had to be replaced four years ago. They have all been in the ground 33 years - the remaining eleven are still solid as a rock. I use several gooey 8" x 8" rail road ties on my fence line and if anything over the 34 years they have been in the ground - they have gotten harder and stronger. They will still be standing long after the barbed wire is dust.

 

[SJay]

4x4's and 6x6's usually have different pressure treating done to them. You want structural pressure treating .60 or above - 4x4 are not .60 unless you order them

 

[Mattt2778]

Don't know that I'd lose a lot of sleep over it, I build decks for living and I can't really think of any times I've run across rotted 6x6s I've seen plenty of rotted 4x4, cedar in particular. I'd say if things are graded well and gutters are maintained you'll be alright but here's an alternative that might be of interest if you're looking to go belt and suspenders Sizes & Literature

One other thing to note is that in the last year or so all the pressure treated lumber I've been getting has been rated for ground contact, even deck boards.

 

[ovrszd]

The only place the post will rot is at ground level. The buried portion won't rot. The portion above ground moisture won't rot. So, if you protect the ground level area from moisture you'll be fine.

I reread your post and still not sure what you are doing with the posts in question?

 

[poncho62]

Probably not popular in todays world, but a lot of old timers would soak the part of their posts that went into the ground with used motor oil. Just sayin'

 

[Rustyiron]

I've never been a fan of PT 6x6, if you've ever cut one, you can see the extent of penetration. The last few times I built with a buried post I used 3 laminated 2x6's, and that was back before the fooled around with the preservative, the CCA day's. Lately I've used a precast concrete pier of poured into sono tubes first. It's also hard to find a straight 6x6 more than 10' long, and that's before you stick it in a hole in the ground with the sun and wind drying it out :laughing:

 

[Cord]

Just so that others know, there are different levels of treatment. ACQ is the home owner stuff so the soccer moms don't freak out when little Jimmy starts sucking on the picknic table. CCA is the older arsenic bearing product that is now limited to commercial applications. The .60 level of treatment is rated for foundation use below grade. Most home center lumber is rated for ground contact or above ground use. With the foundation grade material the treatment will go all the way into the core of the wood. As mentioned, this is not true with the ACQ product when applied to larger members. I have used .60 CCA for some personal outbuilding foundations and I wouldn't hesitate to use the product again. That said, it does have it's limitations. Although permitted by code, I wouldn't use it on a home foundation.

 

[Rustyiron]

:thumbsup:
I am happy to see actual ground contact & burial PT lumber (in smaller dimensional lumber sizes) available, even at the HD locally.
Previously I had to order a full unit at the lumber yard to get this.

 

[SJay]

Just grab the little tag that is stapled to the end of each 6x6 - it will tell you what it is treated for - if it is confusing - just check it online with your phone.

 

[flusher]

I spray the ends and sides of 4x4 pressure treated posts that contact the ground with automobile undercoat and then set them in the hole.

 

[davedj1]

Telephone poses get creosote, just sayin'

 

[Aussiebushman]

How much room do you have around each post? I would brace one at a time with a simple wooden A-frame clamped to the post to prevent it settling while you are working on it, then dig a hole around the base just large enough to concrete in a steel support.

Cut the post just above ground level and bolt the post to the support so the pin of the support will be buried. Backfill the hole with concrete. If you use quickset, it will go off in 20 minutes and you can undo the clamp and move onto the next one

I have done this several times and it always works

 

[TemporaryKubotaOwnerMark]

Concrete them in for even more protection.

Concrete increases decay by trapping water.

 

[Shaneard]

Concrete increases decay by trapping water.

Educate me on this. I'm willing to learn something new.