I'm about to have some 8" cores drilled through a concrete driveway in order to run a fence across it. I'll use 4x4 posts, probably cedar, sunk several feet deep and anchored in concrete.

Should the concrete anchoring the posts be level with the driveway? Higher? Lower? Should I do anything special at the place the anchoring concrete meets the driveway concrete? Any other tips for this project from someone who's done it before?

  • 1
    Definitely not lower than the surrounding concrete or they will collect water which will accelerate the rotting of your posts and also exacerbate any freeze-thaw damage (if that's a concern in your climate).
    – mac
    Feb 27, 2014 at 21:38
  • I'm getting very close to actually making concrete fenceposts. I'm sick of rotten ones (including rotten treated ones and rotten "rot resistant" ones.) It's a bit of a production to get set up to do, and they are heavy and somewhat fragile until cured; but the lure of posts that last is very tempting.
    – Ecnerwal
    May 29, 2014 at 2:57

1 Answer 1


Since there will be now way to insure the concrete will be the same color or will it be able to tie in the texture to make the new pour "go away", neatly slope the concrete up towards the post say about a 1/2" to create a break line where the new concrete meets the old. Try to keep the slope uniform from post to post just so it will look professional. The slope will help drainage, even though the concrete acts like a huge sponge, holding moisture to the post, but it is much better than soil.

New concrete can smear over the old making a mess, but after a few hours, you can carefully clean the old concrete with a DAMP stiff bristle brush, no flowing water, taking MUCH care to not let the brush touch the fresh concrete. You may even wait 6 hrs and still accomplish this task.

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