Thoughts on PT posts in ground.

[Tulex]

Building a free standing lean-to to mount some of my solar panels on. This will have a perimeter of 8 X 24 feet, 8 posts in all.
Posts are 6x6 pressure treated ground contact rated. I'm in western NY, soil has some clay, though that's hit and miss.
I've read quite a bit looking for the best way to prevent rot. I know keeping water away is the biggest thing. Some people say DO put in cement, others say DON'T. Some say to tar, others say it doesn't help at all. Some say to put gravel at the bottom of the hole, others say encase entirely in cement.

Right now I'm leaning toward gravel in the bottom to drain, cement around the posts, and pouring the cement a few inches above ground level to keep water from pooling around the posts.

Any thoughts?

 

[littleharbor2]

Personally, I would take all post ends that would go in the ground and set them in a bucket with some form of Cuprinol brand wood preservative and allow it to be drawn up into the end grain and set them in concrete filled post holes.

 

[Kuma]

Installed many 4x4 pt fence posts in cement on 5 acres that are well over 20 years old and all look very good. The tops show some wear due to sun and rain but nothing structural an inch or two from the tops. I was very close to doing a ground mount and after pricing metal posts/pipes the plan was to use pt posts.

 

[justgary]

If you have concerns about the treatment, buy marine treated posts instead of ground contact. Around here they sell marine "splash" and marine contact rated.

Personally, I would take all post ends that would go in the ground and set them in a bucket with some form of Cuprinol brand wood preservative and allow it to be drawn up into the end grain and set them in concrete filled post holes.

This is a good idea as well, including painting the copper treatment on to just above the ground line.

 

[Tulex]

Soaking in a bucket is probably out, these are 6 X 6 X 16ft long. Gotta weigh a couple hundred pounds. But, coating is an option. Already have the posts, so going marine isn't an option. Post in the ground is very common, odd that there isn't more out there about it.

 

[Zwy]

Soaking in a bucket is probably out, these are 6 X 6 X 16ft long. Gotta weigh a couple hundred pounds. But, coating is an option. Already have the posts, so going marine isn't an option. Post in the ground is very common, odd that there isn't more out there about it.

They used to build pole barns around here with 6x6 pressure treated. Some had cement up the sides in between poles, some didn't.

It didn't really matter too much as the center rots out long before the sides. The reason is the preservative doesn't get thru to the center, it usually makes it in about 1.5 inches. This is why you now see laminated posts, the 2X material allows full penetration thru the wood. If you will be using these, I suggest making a cap for the top of the post to help shed any water. Keep your posts directly under the middle of panels will help also, stay away from the edges. Some water will get thru, that is why you cap it.

As was mentioned, if you have time, then you soak the ends and let it draw up thru the wood. I would not cement the poles in, waste of cement on a wood post. Instead used crushed rock, washed cement rock with fines preferred. This will give some drainage, but heap it up to help shed water. The crushed stone will bite into the wood and help the posts from pulling up and can help with frost heave.

I prefer metal in concrete. If you have access to used oil well pipe, it is the way to go. Cheap and it can be cemented in.

 

[Zwy]

Installed many 4x4 pt fence posts in cement on 5 acres that are well over 20 years old and all look very good. The tops show some wear due to sun and rain but nothing structural an inch or two from the tops. I was very close to doing a ground mount and after pricing metal posts/pipes the plan was to use pt posts.

The old ground contact in the 4x4 was pretty good. I built a deck the first year we were married 34 years ago and those are still on that property holding up the deck. Tops were capped with a 2x4 top railing and that helped. Not cemented in, just crushed rock around the outside and on the bottom of the hole.

 

[littleharbor2]

My point being, and as mentioned above, is allowing the preservative to soak up into the post. If you cant stand the posts up in a bucket then maybe tack a piece of an old terrycloth towel to the bottom so that it will allow you to pour the preservative liberally al over it and, hopefully, it will wick up into the end grain.

 

[Kuma]

Another option, not sure of it was mentioned, are concrete piers, metal standoffs and cross bracing. More work and cost than just sinking posts in concrete or rock.

One other consideration is the OP's age. At my age, anything that will last 20+ years has a good chance of out living me. Even if I live more than 20 years and it fails after 20 I most likely will not care. hahaha Anyway, over building does not always make financial sense.

 

[Tulex]

Another option, not sure of it was mentioned, are concrete piers, metal standoffs and cross bracing. More work and cost than just sinking posts in concrete or rock.

One other consideration is the OP's age. At my age, anything that will last 20+ years has a good chance of out living me. Even if I live more than 20 years and it fails after 20 I most likely will not care. hahaha Anyway, over building does not always make financial sense.

Age is a small consideration. 2 years away from retirement, don't know how long I will live at this location. Obviously don't want to leave a potential issue for a buyer when that time comes, but also don't want to have an issue in 10-20 years if I decide to ride the end out here.

 

[Kuma]

Age is a small consideration. 2 years away from retirement, don't know how long I will live at this location. Obviously don't want to leave a potential issue for a buyer when that time comes, but also don't want to have an issue in 10-20 years if I decide to ride the end out here.

What? Age is a large part of the equation for some of us. hahaha

Maybe in a few years after your retirement, and if you need to budget more carefully for the guessing game of how long you will live and what money is required to get you there, then the intersection of spending money and age will become more than "small". If not, congrats!!

 

[Tulex]

What? Age is a large part of the equation for some of us. hahaha

Maybe in a few years after your retirement, and if you need to budget more carefully for the guessing game of how long you will live and what money is required to get you there, then the intersection of spending money and age will become more than "small". If not, congrats!!

I meant small in that I'm old enough that I'm hoping it will either outlast me or I'll be moving. My house is now worth double what I owe on it, even though we bought it just 7 years ago. We love it here, secluded in the woods on 30 acres. But, we are in western NY. That means winters, and a liberal government, both of which have us wondering how long we will live here.

Either way, I try to save money when I can, but like to do things as right as possible. Research and input upfront, the proper effort when it's time to build.

 

[Rednecktek]

I'm doing that for the array at my camp. I figure by the time it becomes an issue, it'll be my nephews' problem. ??