cedar fenceposts

[Rema1000]

Do postholes around cedar fenceposts need to be filled with concrete, to prevent rotting?  I've got mine dug 3 feet deep (for a light fence shorter than 6 feet), and somehow I don't think I really need 3 feet of concrete to keep it steady.  If it does rot out in 10 or 20 years, it'll be me pulling it back out, so I was wondering if I can skip the concrete altogether and just use dirt or dirt mixed with crushed rock.

[Stephen072774]

I don't think so... I've seen my grandpa do it for years.  Cedar will last longer than other woods because it has a lotta pitch and sap.  I think you can skip the concrete

[3imo]

I don't know about minesota weather (or even if weather is the reason)

but I used to live in central GA and my nieghbor had a 90yr old horse farm. (10yrs ago so I guess its 100yrs now)  his cedar post were put in when the farm was created and still stood.

o'course I wouldn't know if they had been treated(did they treat wood 100 yrs ago?)  and we did pull one or two that had rotted at the base (near the creekbed)

But wadda I know.  Homedepot has books about fenceposts.

[Onlypastrana199]

Coming from the farm kid...you don't need concrete. Mostly thats just used for unstable soil where its really wet and the posts tends to fall out of the ground. Woods like cedar (which is very rare where I live) and locust stay good for years and years because they don't rot away. Softer woods that dry faster will rot even if theyre in the concrete. Concrete sometimes adds to the destruction of the post around the base because the water has no where to go when it rains and builds up around the post.  Just make sure youve got your posts in deep enough cause here the frost will push them out if theyre too shallow.

[RVertigo]

Cement can actually make it more likely to rot...

Dig out a hole wider and deeper than you need and set the depth with gravel...  Put the post in and surround it with gravel.  Leave a few inches of space at the top to fill with dirt.

The gravel should allow the excess water to drain away from the post keeping it dry.  If it's REALLY wet ground, you'll need a lot more drainage.

If you need to use cement to keep the post in place (loose ground, very wet ground), then you can get a metal post bottom to lock into the ground and attach the wood post to that.

[starwalt]

Cedar is used often in the South to reduce the risk of termite damage. There isn't a cubic foot of soil in the south without a termite in it.

All the above comments are A+.

[LimaXray]

You know, I learn so much great shaZam! here

[RVertigo]

Another thing about cedar...

It's generally rather "wet" when you buy it.  Over time it dries out and shrinks, so cementing a cedar post wouldn't work anyway...  It would shrink and have gaps where water would sit and eat at it.

My Father-in-Law covered an interior wall with rough-cut cedar (don't ask me).  Two weeks later he had to cover all the 1/4" gaps with small strips...

The best thing to look for is pressure treated...  You can put it in wet dirt for a few years without worrying about it.  If you have decent drainage around the post, you'll probably never have to think about it again.

[Onlypastrana199]

Pressure treated oak or any of the sort other than locust or cedar is crap...Neighboring horse farm uses pressure treated posts and have to replace them every couple years...we have locust posts that are older than my dad

[RVertigo]

Yeah...  I meant Pressure Treated Cedar...  I guess I forgot a word in there. 

[Stephen072774]

We don't have locust in the south (i'd like to know what that is, hardwood I assume) , be we do have cypress, and thats also used for posts in the south because it resists decay.  Still not as common as cedar.

[Onlypastrana199]

The primary use of black locust wood has been for fence posts which, due to flavonoids in the heartwood, can endure for over 100 years in the soil. The lumber is one of the heaviest and hardest in North America, but the supply is limited due to damage from the locust stem borer, Megacyllene robinae. Black Locust (Robinia pseudoacacia L.) is a nitrogen-fixing legume, native to southeastern North America and now naturalized extensively in the temperate regions of North America, Europe, and Asia. This tree is useful but underutilized for lumber, poles, wood fiber, land reclamation, beekeeping, fuel and forage. It grows very rapidly survives droughts and severe winters, tolerates infertile and acidic soils, and produces livestock feed nutritionally equivalent to alfalfa.

Locust is awesome..aside from the annoying bugs that come with it. They are almost like stink bugs, and they sure don't taste good (Ive gotten a few when cutting hay) Locust grows rediculously straight and it splits easy for split rails, fence posts and the like.

[Stephen072774]

ah, a legume... looks like they are in the south too, i guess i've missed it.  Thanks for the additional info

I'm no tree hugger, but I am a tree lover, I carry one of those pocket guides to trees all the time on hikes... interesting stuff!