How Long Will Cedar Fence Posts Last?

| 12/17/2008 12:00:00 AM

Tags: fence posts, cedar,

If I use cedar trees that I cut myself, is there anything I need to do to them before I can use them as posts for my fence? Also, how long will they last before they rot away?

There are a number of kinds of cedar. Eastern red cedar, found from east of Colorado and into much of New England is actually a juniper, a member of the cypress family. True cedars are members of the pine family.

Junipers are tough, resilient trees that make excellent fence posts, either whole or split. You do not need to treat or debark the posts. As to how long they will last, that depends on how moist the soil conditions are and the amount of freezing and thawing the posts will endure over their lifetime. In the Midwest, Eastern red cedar fence posts have been found to last for decades.

Here is the life expectancy (in years) of some wood fence posts, from the Virginia Cooperative Extension:

Black locust, 20 to 25

Hickory, 5 to 7

zach french
11/9/2011 8:30:54 PM

Call Discount Cedar at (281) 852-8453

zach french
11/9/2011 8:30:15 PM

Great deals on red cedar posts @

sarah hill
8/14/2010 5:29:28 AM

Plastic just tends to trap moisture & encourage decay. Concrete can be protective; but has the potential to work either way. It depends on the type of wood, what treatment its had & the climatic and environmental conditions; under some conditions concrete can wick moisture from the ground into the wood. If using concrete, make sure the top of the concrete is domed so it sheds water, & not dished so that it traps it! If some posts rot off, having a lump of concrete where your replacemt post needs to go is rather inconvenient... Personally, rather than the increased time, labour & expense of concreting, I'd opt to spend the money on top quality posts, that will last.

keith keller_1
8/12/2010 9:33:25 AM

Jan, thanks for this very useful info. I wonder if after charring the bottom 24" would they last even longer if set in concrete or sleaved in plastic?

jan steinman
8/11/2010 4:01:33 PM

Any post will last longer if you char any part that will be in contact with the ground. We put in nearly 2,400 feet of fence a year ago, using metal "T" posts supplemented with cedar posts every 100 feet and at the corners. ("T" posts have no lateral stability.) We built a fire pit and charred the bottom two feet of each ten foot post, rotating as needed. (18" would be in the ground, with an additional six inches above ground "for insurance.") When they looked "done," we propped them up on a flatbed trailer for cooling and inspection. We then used a large propane torch to touch-up and spot-char thin areas. When properly charred, the wood will be "ablative," meaning the propane torch won't raise much more smoke, but the entire surface glows cherry red, because it has become insulative. Think tiles on the space shuttle. Insects and mould hate it. Be particularly careful about the bottom end-grain, which is where insects and moulds will tend to enter, and which tends to be moister, and thus less likely to be adequately charred. That's where we did most of our spot-charring. Charring cedar posts may add ten years to their lifetime -- well-worth doing, if you plan to stick around!

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