Prevent rot in 4X4 Post sitting in Plastic sleeve it System

[Nevika]

Have 6' retaining wall. my contractor installed Sleeve it System (https://www.geogrid.com/en-us/products/sleeve-it-system) sitting on the gravels.
We are planning to have wood railing with help of 4X4 post. each post will be a 4"X4" #2 pressure treated- ground contact.
I am little concern when each 4X4 post will interact with soil and speed the rot in the post. I want this post to last for many year as it would set in concrete.

I am thinking to use a weatherproof vinyl sleeve post which will cover the post entirely from top but buries 1 inch into concrete so there is very less room for fungal growth or rot.
also it would help post from weather.

what would you recommend ?

Thanks

 

[mike93lx]

Wood should not be in concrete or in dirt. Both will cause rot.

 

[Nevika]

That's true but it also depends upon type of application where rot could be prevented for some level. In my application, I can save my post for many year as sleeve is barrier between soil and concrete and the post will be sitting on gravels.

 

[nadogail]

Moisture and wood breed rot. If steel anchors are set in the concrete and the posts are bolted to them with drainage so the posts are not in direct contact with the water they will last a long time. Wooden posts in concrete might last 20 years, if you are lucky.

 

[mike93lx]

A post protector should help, but the best approach is out of the ground.

I would never put wood into concrete though. Use a bracket

 

[tarmy]

Copper green. Get a 5 gallon bucket and soak the end over night in it. I do that to ground contact PT 4x6s I put in ground.

 

[Nevika]

Copper green. Get a 5 gallon bucket and soak the end over night in it. I do that to ground contact PT 4x6s I put in ground.

May be I can go with 4"X6" then. stay last than 4X4

 

[kbs2244]

drainage is needed
set the post in dry gravel
a cap on the top of the post to keep out water would be a good idea

 

[PoorUB]

I would set the posts in gravel, perhaps pea rock.

I have a fence I put up 25 years ago using 4x4 posts treated for ground contact, set in pea gravel. It is still solid.

 

[Nevika]

Thanks, I am still confused, even though without sleeve , How come it can decay wood in ground, it concrete and post both are protected/covered from a thick plastic sleeve. The only problem I am seeing from top where soil has contact with post.

 

[acer66]

Its the continuous drying out getting wet cycles that are causing dry rot which normally happens the most where the post enters the ground.

 

[PoorUB]

Thanks, I am still confused, even though without sleeve , How come it can decay wood in ground, it concrete and post both are protected/covered from a thick plastic sleeve. The only problem I am seeing from top where soil has contact with post.

Concrete hold the water against the post. Gravel lets the water drain away.

I friend on mine has a ceder fence around his yard. Every post set in concrete has been replaced. Corner posts and gate posts weere set in concrete, the run of the fence set in gravel. A couple of the posts just set in gravel have been replaced, but when you consider 200 feet of fence and only a couple posts in gravel have been replaced, versus all the posts set in concrete it makes you think a bit.

 

[Hank11]

https://awpa.com/images/standards/ResidentialInfographic2021.pdf

Keep in mind that an important factor in which treatment you choose will depend on where you are using the posts.

UC4C might be a better choice if its not too expensive or hard to find.

 

[Nevika]

Concrete hold the water against the post. Gravel lets the water drain away.

I friend on mine has a ceder fence around his yard. Every post set in concrete has been replaced. Corner posts and gate posts weere set in concrete, the run of the fence set in gravel. A couple of the posts just set in gravel have been replaced, but when you consider 200 feet of fence and only a couple posts in gravel have been replaced, versus all the posts set in concrete it makes you think a bit.

You mean where soil touches the wood post right at the ground level in my case, right .? So does post protector (https://www.postprotector.com/understanding-decay/) helps or any alternative ( still want to go with Wood due to budget constraints) ?

 

[Natty Bumppo]

Moisture and wood breed rot.

Got to have oxygen as well. Often a 4x4 PT post will rot at ground level where there are all 3...moisture, wood, and oxygen. But that same post 4 feet down is still perfectly fine.

 

[billconner]

Hank11 has the solution - UC4C which is 0.8 pounds of preservative per cubic foot of wood. UC4B would not be bad. 0.6 pcf. Most of what you see in stores is 0.4 pcf.

Decent article on topic: https://www.lampertlumber.com/blog/lumber/what-does-retention-level-refer-to/

 

[PoorUB]

You mean where soil touches the wood post right at the ground level in my case, right .? So does post protector (https://www.postprotector.com/understanding-decay/) helps or any alternative ( still want to go with Wood due to budget constraints) ?

I am not sold on that post protector. It will still trap water like putting the post in concrete. It light protect against a weed trimmer, but I am not convinced it will help for rot.

Put the post in gravel and a couple inches from the surface use soil to grow grass. The gravel below will drain the soil and keep it fairly dry.

 

[mikedodge]

If the vinyl sleeve can get moisture inside it that's not good either because it can hold the moisture against it.
Gravel right up to the surface is the best way. It'll get wet but dry quicker and also help lock the post in place.

I built a fence in 2009. I thought the un treated un painted fence boards or 2x4s I nailed them to would need to be replaced over time but instead it's the pressure treated 4x4 posts. Last year some were noticeably soft right where they enter the ground. This week the first one broke at that point leaving that chunk of fence partially toppled over. The base of the posts are in gravel concrete mix with with soil on top, the only part that rotted is right where the post enters the ground. Above and below that level are still good.

 

[Jbullfrog]

Having looked at the link, you provided, you should be fine with the posts in the concrete, as that is how the system is designed. I would not recommend putting the vinyl into the concrete, at it would make it really difficult to repair or replace, if something happened to the post cover (think mower/ trimmer, fire). I would suggest wrapping the post, or treating it from the concrete, maybe 4" or so up with a sealer, and then topping the concrete with pea gravel around the post and vinyl to ensure drainage.

 

[mslim]

End grain is a sponge. Even in dry SoCal the codes required a patio cover wooden vertical support to have an airspace between it and the concrete slab. I can't tell you how many wooden fences in our area were blown over by Santa Ana's when the post rotted.

We used a Simpson elevated metal bracket. Do your footing however is customary and legal in your area and set the Simpson in the footing.

https://www.strongtie.com/postbases_capsandbases/category

 

[P0234]

It's funny because I see whole towns on the coast with houses on treated wood directly in the ground. Some of them have to be over 70 years old.

 

[bb29510]

ii remember farmer soaking their fence post in used motor oil

 

[mike93lx]

It's funny because I see whole towns on the coast with houses on treated wood directly in the ground. Some of them have to be over 70 years old.

Despite there being varying levels of treatment? It's not all the same

If the OP is buying wood rated for the same exposure as what you mentioned, absolutely send it.

I doubt that though.

 

[Nevika]

Thanks everyone for all your experience and suggestions.

How about using tricks by this man ?

 

[billconner]

Creosote is great stuff (as is asbestos). You can find recipies on line for making creosote. A tank and dipping would be probably best method.

 

[P0234]

Despite there being varying levels of treatment? It's not all the same

If the OP is buying wood rated for the same exposure as what you mentioned, absolutely send it.

I doubt that though.

Just saying it’s possible for wood to be in very wet ground for a long time in response to people saying you can’t put wood in the ground. I think we agree that some sort of treatment is necessary and it’s not what you get on Home Depot lumber. That **** is now just sprayed to look like it might be water treated.

 

[PoorUB]

Thanks everyone for all your experience and suggestions.

How about using tricks by this man ?

Years ago my dad would take new cedar posts and set them in a barrel with used motor oil and diesel fuel to thin it out. He would stuff as many posts as he could in a barrel and forget about them for a few weeks, then take them out and let them drip into another barrel before using. He always had posts soaking! The EPA would probably be all over him today, but this was back in the 60's, probably why we have the EPA today!

 

[Nevika]

DO I need to wait for the 4X4 wood to dry before i apply any oil or wood preservative and set in concrete ?

 

[mike93lx]

DO I need to wait for the 4X4 wood to dry before i apply any oil or wood preservative and set in concrete ?

Yes. I would wait 20 years before setting in concrete. Should give you about 25 years of use

Seriously though, fresh PT is extremely wet. Any drying you allow it to do before coating will help it and the coating last longer

 

[Uncle murph]

I would set the posts in gravel, perhaps pea rock.

I have a fence I put up 25 years ago using 4x4 posts treated for ground contact, set in pea gravel. It is still solid.

The wood you used 25yrs ago had arsenic in the preservative,good stuff,the wood being sold now has the enviromentally safe version of preservative.Its ****.

 

[wssix99]

Thanks everyone for all your experience and suggestions.

How about using tricks by this man ?

This works really well and the posts I have treated like this have lasted decades in the dirt (and concrete). I used foundation coating.