Gate Post

[Hardrock40]

Built 2 gate post for a 14' farm gate with an electric opener.
4" Schedule 40 steel pipe with weld on caps, the caps are schedule 40 from the link Chad provided ( King Metals) Thanks.

The gate was breaking the screw in hinge pins, its has a lot of pressure on the hinges.

So I have a quick question. What diameter hole would be best for setting the main post in concrete? It will be three feet deep.

[wroughtnharv]

Built 2 gate post for a 14' farm gate with an electric opener.
4" Schedule 40 steel pipe with weld on caps, the caps are schedule 40 from the link Chad provided ( King Metals) Thanks.

The gate was breaking the screw in hinge pins, its has a lot of pressure on the hinges.

So I have a quick question. What diameter hole would be best for setting the main post in concrete? It will be three feet deep.

I have a tendency to overbuild according to some people. But I have a saying about gate post holes. "you only regret digging it too deep one time."

Walk gates are four feet deep and one foot across.

Small drive gates are six to eight feet deep, twelve to sixteen inch holes.

Automated big gates, three hundred pound plus/ fourteen feet or more, two foot diameter by ten plus feet deep.

There's nothing worse than having to go back and redo a hinge post because you went cheap up front.

[Hardrock40]

Thanks for being up front there wroughtnharv.

This gate I would guess is 150lbs to 200lbs max as I can pick it up and move it around but not far.

Looks like from your post I need to go a few more feet down. This would be just a minor fix of adding another piece of pipe to the bottom.

Three feet seems a bit shallow too me also, thats why I needed some good advise.

Thanks.

[Jim-TX]

Going deeper will give you more strength than going bigger. Follow Harv's advise, he's well experienced.

[davinci2010]

Have you thought about installing a helper wheel on the end of the gate opposite the hinges? Seems like it might take some of the strain off the hinges and support post. Also takes some of the sag out as things wear in over the years.

[admweld]

Don,t you guys put the post in the hole then pour concrete around it to anchor it like say 3/4 the depth of the hole?

[davinci2010]

We usually fill the hole all of the way with concrete. A heavy gate, and particularly and long and heavy gate, needs a pretty deep hole and concrete to last. A gate this size probably needs a hole 3ft. deep + and at least 18" dia. Helps if you have an auger.

[Hardrock40]

I like the helper wheels and if it were mine I'd have one. The wheel would only contact the ground the last couple feet being closed but still that would be a plus.

I had to use post hole diggers. The original post was a part of columns that were put in with concrete also and I got to get this one close so using an auger was out. Had to break off some concrete anyway and dig beside it.

With that being said, the hole is only 4 feet deep, 12 to 16" round. Thats alll the post hole diggers could do. Waiting to pour it on Saturday, and now the rain is filling it up. Got most of the water out yesterday but more will come.

[Pontiac Freak]

putting up barbed wire fence we would go down 4 foot for our corners that were holding up 1/4 mile to 1/2 mile of fence. We never used concrete, we tamped every shovel full with a spud bar. Those fences have been standing for 20+ years. The wood rots away before anything else gives. From my experience you have to make the ground hard around the pole to get it to last.

[wroughtnharv]

Here's some of the logic I use when I consider the size of gate post and footer.

Soil, what works in sandy soil won't work in serious clay. The same is true in rock. In granite like we had in California I was comfortable with short small diameter holes because the rock was better than concrete for stablity.

Post, I want it to be much stronger than any forces possible on the gate over time excepting accidents etc. That's why I use so much six inch schedule forty pipe.

Concrete, it makes the post thicker where it needs to be thicker. If you have a four inch diameter post and you try to move it sideways it's a lot easier than something sixteen inches in diameter. That's why we have wide holes. They make moving the post sideways more difficult to do.

Depth of the footer or post hole, I have an example I use on clients. I take a pencil and put an inch of it between their fingers and tell them to grip it firmly. I put pressure on the pencil at the top and let them see how little control them have over movement of the pencil. Then I have them grip the pencil in their palm and make a fist. We repeat my attempt to move the top of the pencil.

They usually understand why I like deep holes.