We currently have a 9ft wide, 4ft high double wooden picket gate using 4ft 4x4 (100x100) gateposts. We are considering replacing these with Buxton style wooden gates (solid wood up to a certain height then an open header).

If the height of the gate is increased to either 4ft 6in or 5ft, could the existing 4ft gateposts be used or would we need to dig them out and replace them with taller ones?

The gates are under a 9ft high hedge which arches across the drive, so there is no requirement for the posts to match the height of a wall or fence, hence they don't need to reach the top of the gates.

I don't recall the depth of the existing posts, but, in over 10 years, they have shown no sign of movement so assume they are solidly embedded; I'd guess at least 2ft deep.

Since I don't have suitable pictures, I've modelled the existng gate and one of the designs we've been looking at in Fusion 360 to illustrate the current gates and proposed 5ft gates on 4ft gateposts. To save time in design, I have omitted the hinges and lock.

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Existing 4ft picket gates on 4ft posts

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Suggested 5ft Buxton gates on 4ft posts

  • Welcome to Home Improvement! Please edit your post to include some pictures, or at least a drawing of what you've got and what you're after. I'm not sure how you're trying to add 6-12" to the top of a post, or how much weight it's expected to support, so it's hard to give a recommendation on what would or wouldn't work in this case.
    – FreeMan
    Jun 1, 2020 at 15:50
  • @FreeMan I've been a research physicist and worked a lot with computers and electronics and although I've done some DIY wouldn't consider myself a carpenter. What I'm looking for is some kind of formula (or rule of thumb) to indicate what size gate 4ft high 4x4 posts could support. Obviously, the hinges could be placed at the top and bottom of the posts and the gate could extend above them by 1ft without a problem and, also obviously, I won't be extending the posts as it be mostly cosmetic! But how do I estimate the strength of the posts and whether the weight of the gate would be too much?
    – StarNamer
    Jun 2, 2020 at 21:50
  • Ah, those images make much more sense! I'm very impressed that those 4x4 posts haven't sagged or warped in the last 10 years! I'd imagine that there's more than 2 feet in the ground... I'm not the guy to answer your question, but I'm sure someone will be able to sooner, rather than later.
    – FreeMan
    Jun 3, 2020 at 10:58

1 Answer 1


No sagging in 10yrs? Go for it. Just check the base of each 4x4 post where wood & concrete make contact to make sure there's no dry rot. Worse case scenario you can add caster (wheel) to the bottom of each gate where the two gates meet in the middle. This will take most of the load off the post if sagging becomes a concern

  • Agree with post above. If you don't care about the appearance, the only issue is if the posts can support the weight (or torque which is proportional to the weight). If the gates weigh the same there will be no difference in the torque placed on the posts. And if they have held up for 10 years without moving they can likely support more if there is no decay.
    – Kevin
    Jan 29, 2023 at 0:15

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