Rotten fence post

This past spring we noticed the fence post that our gate hung on was loose. By summer the whole post would swing wildly back and forth as we opened and closed the gate. We installed this fence five years ago to the month.

Lee finally dug a hole by the post so we could see what was going one. It’s rotted and about to break off at ground level. None of our other wood fence posts have displayed this sort of problem so hopefully it’s just a one-off. The posts are all from a small local business with a reputation for quality. We haven’t fixed it yet as we are mulling over how we are going to repair it.

Rotten post

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12 Responses to Rotten fence post

  1. Snowbrush says:

    It’s cedar, I suppose, as I can’t tell that its treated. I’m so sorry this happened, and it would be the very post that’s the most problematic to replace.

    • lee says:

      These are ACQ treated Doug Fir posts. Building a fence is too much work to use untreated wood. In 1949, Oregon State University started a fence post trial which is still in progress. They tested readily available western species (and a few imports like Osage Orange), treated and untreated. The results were that untreated heartwood cedar posts failed within 20 years. The only local species that did well without treatment was Western Juniper, which mostly exceeded 30 years. ACQ treated Doug Fir should have a similar lifespan.

  2. Rich says:

    I’d guess that opening and closing the gate made it move back and forth just enough over the years to leave a small gap that let water in around the post which led to it rotting.

    If you get some gravel and tamp it around your post when you replace it, the gravel will hold the post a little tighter (almost like concrete) and it will let the water drain away from the post (unlike concrete).

    • lee says:

      This sounds like a good theory. The gate has actually spent a lot of it’s time open (propped up to take the strain off), but there have also been long periods of daily opening and closing. We are talking about putting a human-sized gate in next to the big one so that daily access will cause less wear on the fence in the future.

  3. Sandra says:

    I stumbled on to your blog by accident and this one about your fence post reminded me of when my dad use to pay us kids in fruit to touch the electric fence to see if there was a short or not, zzzap.

    • lee says:

      Ah, that’s terrible! Robin hates being shocked so bad that even pomegranates wouldn’t have tempted her to do this.

      I have a meter which tells me if the fence is hot, and unlike screaming children it also tells me the direction and magnitude of the short.

  4. Steve says:

    We have gone to metal post because of this. We get about 15 years out of any wood. We have taken to fixing existing fence with metal poles set in concrete, that way you don’t have to redo the fencing. Looks like you have a hole dug, slide or tamp in a metal post or channel iron and pour concrete.

    • lee says:

      I considered metal posts when we first built the fence, but I can’t easily build H-braces out of metal and only an H-brace arrangement can handle the strain of high-tensile wire. There’s a ranch about 10 miles from here that has prefabricated welded steel H-braces at all the corners, but I’d hate to think how much they spent for them. None of our other posts are showing signs of rot, so I’m hopeful this was a one-off.

  5. Lee, I’m working out the plans for a new fence for our garden and fruit trees now. I really found your experience helpful.

    After 6 years, how effective has the wires on the top 4 ft been for keeping the deer from jumping in? I’m wanting to do something similar.

    Also, did you wrap your corner post that rotted in plastic when you placed it in the ground? I don’t see any plastic in the photo you posted.


    • lee says:

      Just the other night we watched a doe and two juveniles run along the outside of the fence and Robin commented on how tall they seemed, but we’ve never had a deer inside the fence in all this time. I especially credit the high-visibility polycord line at the top, which is about 6’6″ off the ground. We drilled the anchors for this cord a little too close to the tops of the posts and a couple have broken out. That’s the main thing I would change if I had it to do over, but otherwise it’s in perfect shape.

      The rotted corner post was not wrapped in plastic. (It’s part of the goose pen, not the garden.) I only wrapped the ones in the garden over an excess of concern about treated wood. I haven’t wrapped any posts since then, although I plan to do it again with the rest of the posts I put in. Anything to improve rot resistance seems like a good idea.

  6. Thanks Lee for reply. Can you give me more details on your high-visibility polycord line please? What diameter of cord/rope did you use? What color? was it against the wires or a couple of feet spaced out from it? What type of anchors did you use?

    Thanks so much.

  7. Tom says:

    Hi Lee and Robin, I would not wrap a fence post in plastic. Rain or snow hits the post, then runs down between the post and the plastic which will keep the post extra moist and make it rot sooner, likely. Kinda like a rubber glove. They keep your hands dry, but if ANY water gets in there, your hand is super soaked. Concrete does the same thing, holding moisture at the post and accelerating rot. Use steel if you can and if not, be sure the final dirt tamping around a treated post slopes away on all sides, draining water away from the post, not pooling it in a doughnut shaped pond around the post. All that said, in some applications I’ve had good luck pounding steel posts in right along side the rotted post and nailing or bolting them together. Worth a try in the right situation.

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