# What to put on 4x4 posts to make them last longer?



## Shadow11 (Mar 18, 2015)

Is it a bad idea to put sealer or tar on 4x4 fence posts to try to make em last longer?


----------



## 660griz (Mar 18, 2015)

If they are completely dried, I don't see why it would hurt. 
I sealed my deck after it sat for about a year to get all the moisture out. You probably don't need to wait that long but, that is what I told my wife.


----------



## Crakajak (Mar 18, 2015)

above ground or below ground?


----------



## Shadow11 (Mar 18, 2015)

These will be put about 3' into the ground. They r treated, but i know that even treated posts dont last all that long under ground. Ive heard some people say that you need to coat the underground end with tar or some kind of sealer, and others say no because water will collect inside the bottom of post if you do that. Should i do the entire post? Just the in ground end? None at all? Advice appreciated.


----------



## Luke0927 (Mar 18, 2015)

Diesel fuel and old motor oil always worked well, that was the old way for country folks. Not sure many folks do it that way now.

Probably just tar them up and bury.  If you are concreting slope away the concrete at the top where water doesn't stand at the base of the post.


----------



## Wild Turkey (Mar 18, 2015)

You do realize there are 2 types of pressure treated lumber.
Above ground and below. Get the below ground grade 4x4's


----------



## j_seph (Mar 18, 2015)

Maybe 6 inches of so of gravel in bottom of hole would help also


----------



## Shadow11 (Mar 18, 2015)

Wild Turkey said:


> You do realize there are 2 types of pressure treated lumber.
> Above ground and below. Get the below ground grade 4x4's



No i didnt know. The only place i have around here to look at em is lowes, and they only have one type of 8' treated 4x4 to choose from. They have them in the lumber section as well as the fence section. They are the exact same price, so i assume they r the same 4x4s. The only other thing they have that r 8' r landscape tembers.


----------



## fireman32 (Mar 19, 2015)

Below ground should be treated to .40


----------



## Crakajak (Mar 19, 2015)

Shadow11 said:


> No i didnt know. The only place i have around here to look at em is lowes, and they only have one type of 8' treated 4x4 to choose from. They have them in the lumber section as well as the fence section. They are the exact same price, so i assume they r the same 4x4s. The only other thing they have that r 8' r landscape tembers.



The tag with the sku# on it should say if it is for above ground or below ground usage.


----------



## shakey gizzard (Mar 19, 2015)

If possible, use one of these with a concrete pad! If not, tar and wrap in plastic to an inch above grade. The "New" PT is nothing like the old!


----------



## Shadow11 (Mar 19, 2015)

Ok thanks. If i can find the below ground grade, how long can i expect them to last?


----------



## The Longhunter (Mar 19, 2015)

Shadow11 said:


> Ok thanks. If i can find the below ground grade, how long can i expect them to last?



Supposedly 20-30 years depending on who is doing it.  I have some that barely made half that.  Either PT was weak, or termites are getting better.

You can extend the life by putting a shovel .full of gravel in the bottom of the hole to let water drain away.

I learned that there are "ag treatments" that are heavy but you won't find them at the big boxes.
 c
I don't know for a fact, but I wonder if soil conditions in Georgia (highly acidic) affect longevity?


----------



## Wild Turkey (Mar 19, 2015)

landscape timbers are a no no for posts. They rot real quick


----------



## fireman32 (Mar 19, 2015)

The Longhunter said:


> Supposedly 20-30 years depending on who is doing it.  I have some that barely made half that.  Either PT was weak, or termites are getting better.
> 
> You can extend the life by putting a shovel .full of gravel in the bottom of the hole to let water drain away.
> 
> ...



I think the quality of lumber has a lot to do with it.  Trees growing to fast, makes them weak.


----------



## Atlanta Dawg (Mar 19, 2015)

fireman32 said:


> Below ground should be treated to .40



Exactly Right On The .40  !  

And-don't use landscape timbers-not if you want them to hang around for a few years.  Do use the .40 and if you cut the end off of it for some reason-not a bad idea to treat the cut end with something.  I have seen termites - not often-but occasionally-eat up a treated 4 x4.


----------



## tv_racin_fan (Mar 19, 2015)

Gravel under the post is the correct method when putting a post IN the ground.


----------



## jimbo4116 (Mar 19, 2015)

Shadow11 said:


> No i didnt know. The only place i have around here to look at em is lowes, and they only have one type of 8' treated 4x4 to choose from. They have them in the lumber section as well as the fence section. They are the exact same price, so i assume they r the same 4x4s. The only other thing they have that r 8' r landscape tembers.



Here is some info to help.  Go to a good lumber yard.

http://www.awpa.com/references/homeowner.asp

What do the AWPA Use Category designations mean?
The Use Categories are a shorthand method of describing the various hazards to which wood products may be exposed.  A brief description of the Use Categories is shown, but if you would like additional details on the AWPA Use Category System, please download this excerpt from AWPA Standard U1.

Use Category	Brief Description
UC1	Interior Dry
UC2	Interior Damp
UC3A	Exterior Above Ground, Coated with Rapid Water Runoff
UC3B	Exterior Above Ground, Uncoated or Poor Water Runoff
UC4A	Ground Contact, General Use
UC4B	Ground Contact, Heavy Duty
UC4C	Ground Contact, Extreme Duty
UC5A	Marine Use, Northern Waters (Salt or Brackish Water)
UC5B	Marine Use, Central Waters (Salt or Brackish Water)
UC5C	Marine Use, Southern Waters (Salt or Brackish Water)
UCFA	Interior Above Ground Fire Protection
UCFB	Exterior Above Ground Fire Protection


----------



## jiminbogart (Mar 19, 2015)

Shadow11 said:


> These will be put about 3' into the ground. They r treated, but i know that even treated posts dont last all that long under ground.



Order your posts from a place that treats them.

I would suggest ordering CCA treatment that is rated for UC4C Ground Contact Extreme Duty. That is what I ordered for my pole barn posts. 

Some light reading: http://www.awpa.com/standards/U1excerpt.pdf

These are CCA treated and have a 30 year warranty: http://www.greatsouthernwood.com/products/farm-ranch


----------



## jiminbogart (Mar 19, 2015)

shakey gizzard said:


> The "New" PT is nothing like the old!



That is correct.

You can still buy the "old" though.


----------



## Oldstick (Mar 21, 2015)

Wild Turkey said:


> landscape timbers are a no no for posts. They rot real quick



I can definitely add an amen to that comment.  I thought I would be smart and save some $$ that way on a small fenced area in our back yard.  Half of them are broken already in less than 5 years.


----------



## 7Mag Hunter (Mar 22, 2015)

I put concrete in each hole (2' deep) when i did our fence about 5 yrs ago....

Dug hole, set PT post in added water and concrete and used steel bar to mix concrete.....6x6 posts on end and 4x6 posts in center. 2x6 for rails.....Rock solid..

After 2 mos, i used Behr stain.....


----------



## Shadow11 (Mar 23, 2015)

I went back to lowes. The 4x4 they sell in the fence post section is #2 grade, .15, and they are over 8.00 ea. Here is the label...














What i need, is for 5' to be above the ground. I need 2 of them to be able to support up to 75 lbs between a 20' span, on a single wire attached to the top of each pole. 

Do you think these metal posts can handle the weight. They are 7' long. I was thinking of maybe digging a 1' deep hole, driving the posts 1' through the bottom of hole, and filling the 1' hole with concrete. Will that work? They are cheaper, and it will be a lot less digging.


----------



## shakey gizzard (Mar 24, 2015)

If your making grape vine supports, I'd go with old telephone poles. Those metal posts wont last! IMO


----------



## jimbo4116 (Mar 24, 2015)

shakey gizzard said:


> If your making grape vine supports, I'd go with old telephone poles. Those metal posts wont last! IMO



The local emc will give old poles to you if you can haul them.  Have them cut into 12' lengths to haul on small trailer.

Might want to check with the local utility company.


----------



## fireman32 (Mar 24, 2015)

.15 #2 will not last long, an actual t-post has a tendancy to bend.  Utility companies will give away free used utility poles, around here they get snatched up pretty quick.  If you can find a rail road guy, he could get you a few cross ties, they'll last an extremely long time. Pretty sure they're close to 8 feet long.


----------



## Big7 (Mar 24, 2015)

jimbo4116 said:


> Here is some info to help.  Go to a good lumber yard.
> 
> http://www.awpa.com/references/homeowner.asp
> 
> ...



LOT of knowledge right here!

I did not go through the entire thread but did notice
one that I have first experience with..
Diesel fuel and oil.. Anything you can find.

Waste  transmission fluid, whatever petroleum
you can find. Synthetic, all the better.
Kerosine is high right now, but if you got some 
old, throw it in there.

Put in a cut of PVC and soak a day or two..

Be here a long time after we are all gone...

CHEAP TOO.... 

No funnin'.. three days will do it.


----------



## ebryant (Mar 24, 2015)

TC Flowable from Tractor Supply is effective for termite treatment. Spray the post and the soil as it is refilled. It will give you an extra head start of about 5 years before the termites get to it.


----------

