Results 1 to 14 of 14

Thread: How to mount 4x4 fence posts?

  1. #1
    Join Date
    Sep 2006
    Location
    Las Cruces, NM
    Posts
    2,036

    How to mount 4x4 fence posts?

    I'd like to put some 4"x4" by 3 ft fence posts on some sort of mount over small concrete pads. That way my posts wouldn't rot so quickly on the bottom. (I want to replace a fence with about 30 buried cedar posts that are deteriorating - due to the warm climate or the lumberyard not having the right kind of cedar?) Most of the inexpensive post mounts at the hardware stores say they are not recommended for use with posts that are not supported at the top. The mounts that are recommended for fence posts have big U-shaped sides that fit around the post. However, this type of mount is very expensive. Is there an inexpensive option for setting the posts?


    I've though about cutting lengths of pipe, boring a long hole in the bottom of the post to insert the pipe and setting the pipe in concrete. (Would that work? Is it practical to bore big holes?)

  2. #2
    Join Date
    Feb 2009
    Location
    New Haven County, CT
    Posts
    261
    Are there railings between the posts?

    What do the posts hold up? I know you mentioned you cant use the mounts that require the posts be supported at the top, so I cant tell if you have anything between the posts.

    If you DO have something between the posts (railings, etc), I had good luck with the standard galvanized 4x4 Teco plate from HD/Lowes. It has a lower portion that sits on the concrete and an upper portion that nails to the bottom of the 4x4. You can drill a hole in the concrete, get epoxy and then drop in a threaded rod, then bolt the Teco plate to the threaded rod.

    End result is post about 1" off the ground. I used this when adding a step platform from my patio to my sliding door.

  3. #3
    Join Date
    Jan 2008
    Location
    Bradenton, Fl
    Posts
    499
    The best way to build a wood fence is to use sonotube concrete forms and insert the fence post in them and fill with concrete.

  4. #4
    Join Date
    Nov 2006
    Location
    Sebastopol, California
    Posts
    2,319

    The issue is leverage

    Conventional setting of fence posts - around here, normally 2 feet down for a post that will be 6 feet above grade at the top (more for the post on the hinge side of a gate) - provides leverage to resist pressure on the fence. Those expensive metal brackets give you the leverage effect without sinking the post in the ground.

    Pipe as the fence post, with a wooden post impaled on it, is workable, if you have the tools and the capability to drill accurate holes about halfway up the post - say, a powerful 1/2" drill, a suitable (long!) bit, and some kind of jig to direct the bit properly. I'd price out the pipe compared to the expensive brackets first, though; and if you don't have the tooling, you'd probably find that the cost of tooling up for a pipe approach would be more expensive than the brackets.

    Some people use pipe and then "skin" the pipe in some manner with wood. This would be another approach, also labor intensive (the railings on my front steps are pressure treated 4x4s skinned with redwood, and getting the redwood set right took me about three times longer than setting the posts), but perhaps less of a high-wire act than drilling an accurate three foot long straight hole, say 2-1/2" in diameter in a 4x4 post.

  5. #5
    Quote Originally Posted by Robert Parrish View Post
    The best way to build a wood fence is to use sonotube concrete forms and insert the fence post in them and fill with concrete.

    I just dig a straight sided hole.
    Then I pack the base with large gravel about a foot deep.
    Then I put the post in place right on the gravel (that way any water that gets in can get out) , level it and pour the concrete to below grade by a few inches.
    I trowel the concrete so it slopes away from the post.
    Then I back fill with earth when the concrete's hardened enough and let the grass grow right up to the post.
    I use PT.

    If I really care about the job I'll soak the post end that'll be in the soil against the gravel in old crank case oil cut with mineral spirits for a while. The wood will take that up and it'll slow moisture transpiration.

    Were the wood not PT, I'd terminate the concrete above grade by building a little box that I'd put on the upper end of the concrete a few inches below grade and fill that and trowel to slope away from the post.
    That way the only concrete that shows above ground is that neat little box shape. I suppose a chunk of Sono' would work fine but I sort of like square.

  6. #6
    Join Date
    Oct 2006
    Location
    Mid Michigan
    Posts
    3,559
    The Borgs sell a steel stake the is made to replace rotted off posts. The steel is driven into the ground and the post is fastened to the steel. Works great in a fence where there are a few rotted post bases. Saves tearing out the fence or ripping up the cement. Check them out to see if they will do the trick for you.
    David B

  7. #7
    Join Date
    Sep 2006
    Location
    Las Cruces, NM
    Posts
    2,036
    The posts will have rails between them. It's a like a picket fence but with large pickets about 3 inches wide and 2x4 rails about 5' long. (I can change this, since I must rebuilt the fence.)
    If having rails cancels the warning about "unsported at the top", I'd really like to use the simple post mounts.

    I've seen a metal stake with a U shaped bracket that holds a post. But last time I looked they were about $40 each. Is there a different kind?


    I agree that burying a post 2' or greater (without concrete) gives it adequate support. That's the way the current posts are set. But the buried end of the post deteriorates. My yard has about 3' of dense brown clay. The climate is dry, but when it does rain (or the lawn gets watered) the clay holds moisture for a long time.

  8. #8
    Join Date
    Feb 2009
    Location
    New Haven County, CT
    Posts
    261
    The only "drive into the ground" metal post holders Ive seen ARE that expensive, unfortunately.

    If you wanted to avoid burying the post directly at all costs, your best shot is to pour footings (SonoTube+concrete) and insert a j-bolt to bolt a Teco plate to. If the posts come out of the concrete OK, you might be able to fill the void from the old post with concrete and add the j-bolt, so you dont need to dig brand new holes.......not sure how well the new concrete would stick to the old. Thats probably the most economical fix, as SonoTubes, concrete and j-bolts are pretty cheap. Definitely no where near 40.00/post.

  9. #9
    Join Date
    Sep 2007
    Location
    Bucks County, Pennsylvania
    Posts
    940
    I have never used concrete to set fence posts - even 8' heavy board and batten fences that required 6x6 posts.

    What provides the support is the depth of the post -- concrete actually promotes decay of the wood as it holds moisture and extends the drying time. It is not needed.

    Pressure treated lumber will also last longer than cedar in this application.


    I used -- or tried to use one of those long spike holders for a mail box post -- but I had to remove it and install a metal post.

    Covering a pipe can be done - but it is a lot of work

  10. #10
    Join Date
    Sep 2006
    Location
    Las Cruces, NM
    Posts
    2,036
    SonoTube and j-bolt, I understand. What is a Teco plate?

  11. #11
    Join Date
    Feb 2009
    Location
    New Haven County, CT
    Posts
    261
    Quote Originally Posted by Stephen Tashiro View Post
    SonoTube and j-bolt, I understand. What is a Teco plate?
    I think originally they were by Teco, now SimpsonStrongtie

    You want something like this:

    http://www.strongtie.com/products/connectors/pb-pbs.asp NOTE these dont need J-bolts but might be harder to find than just going to HD/Lowes

    or this:

    http://www.strongtie.com/products/co...ba-abe-abu.asp
    Last edited by Chris Harry; 06-10-2009 at 9:21 PM.

  12. #12
    Join Date
    Nov 2006
    Location
    Fallbrook, California
    Posts
    3,562
    My wood fence is built on metal posts.

    See: http://contractors.masterhalco.com/C...PostMaster.pdf
    Don Bullock
    Woebgon Bassets
    AKC Championss

    The man who makes no mistakes does not usually make anything.
    -- Edward John Phelps

  13. #13
    Join Date
    May 2007
    Location
    Fort Smith, Arkansas
    Posts
    1,984
    The metal brackets state they are not for unsupported tops such as fences. Are you recommending their use anyway or is a fence with stringers considered to be 'supported'. Just curious because I just had an overgrown hedge removed and want to build a 3-4 foot high picket fence in its place and was considering using wood covered metal posts but this would work as well if its' actually practical.

  14. #14
    Join Date
    Apr 2008
    Location
    Spokane, Wa.
    Posts
    164

    posts

    Read Cliffs reply.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •