Fence post footing options

Discussion in 'Landscape Architecture and Design' started by Stonehenge, Apr 1, 2002.

  1. Stonehenge

    Stonehenge LawnSite Bronze Member
    from Midwest
    Posts: 1,277

    I've always used quick-setting concrete when making footings for small fences, arbors and the like, but more and more I'm finding competitors simply using crushed stone down to the frost line. Seems faster and easier, and I can see how water might drain better (though it would also attract water better).

    What do you use - concrete or crushed stone, and why?
     
  2. paul

    paul Lawnsite Addict
    Posts: 1,625

    Unless it's a steel post, we are seeing more LA's want gravel too. The problem is rotting from what I hear, seems concrete holds moisture against not letting it dry out while gravel does.
     
  3. diginahole

    diginahole LawnSite Member
    Posts: 249

    I never set fence posts in concrete. Concrete heaves right out of the ground. I set fence posts with Granular A (road base). Gravel will drain and prevent the post from jumping out of the ground. Watch the power company set light standards, they don't set them in concrete they use gravel. When the concrete moves up in the hole from the frost it shaves dirt of the side and falls under the concrete causing it to lift higher and higher out of the ground each winter.

    There is less labour to set with concrete ( you don't have to compact), but you save on materials when setting post with gravel.

    One trick that we use to compact the gravel is to drop the end of the hose in the hole before you fill it with gravel. After the hole is filled turn on the tap and pull the hose out slowly. Get the gravel a little wetter than you would when wetting patio base. It packs in real tight with a pinch bar or small head (3" x 3") tamping bar.
     
  4. NNJLandman

    NNJLandman LawnSite Bronze Member
    Posts: 1,306

    I agree with diginahole, a like Quary dust compaction is a good base type. Fine grinded rocks like gravel works great. Just make sure to tamp it down in there well!
     
  5. wxmn6

    wxmn6 LawnSite Member
    Posts: 163

    I have done dozens and dozens of fence posts installation in the past. What I have learned is that it is the best to leave about 8" to 12" of soil or gravel uncompacted on the bottom, then after that, start compacting up to the top. It will make the post stronger and it would be hard to flex the post back and forth. If you compact the soil and gravel right at the bottom, it would usually make the post weaker at the top, making it easier to flex back and forth. Then a few years later it would become very loose.
     
  6. eskals

    eskals LawnSite Member
    Posts: 210

    Concrete and fence posts is a bad idea. As the wooden post shrinks, a small gap is created in between the post and the concrete. This gap traps water and contributes to rot.

    When installing fence posts, we often use pea gravel. We excavate, place a concrete brick at the bottom, place the post, and then fill with pea gravel. One nice thing about using the gravel, is that as you hammer on the post, it actually becomes stiffer, as the vibrations from hammering will settle the pea gravel in around the post.

    Eric
     
  7. dan deutekom

    dan deutekom LawnSite Senior Member
    Posts: 424

    It seems that we are all in agreement about using gravel instead of concrete. I have never seen a fence post in gravel heave out of the ground but every one in concrete does. Eric what purpose does the brick serve under the post? I just use a little gravel under the post and never had a problem.
     
  8. Stonehenge

    Stonehenge LawnSite Bronze Member
    from Midwest
    Posts: 1,277

    Looks like we'll be changing a methodology this year......;)
     
  9. eskals

    eskals LawnSite Member
    Posts: 210

    I think the concrete brick is to keep the post out of any water that may accumulate at the bottom of the post hole.

    Eric
     
  10. NNJLandman

    NNJLandman LawnSite Bronze Member
    Posts: 1,306

    I think that a gravel base works best for me. Still unsure what to do about metal post. Concrete is ok but after i hardens u can pretty much push it right out.
     

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