I am getting ready to build a 6' tall 80' long wooden fence, but instead of 4×4 wooden posts I am going to use metal fence posts. The fence will have 1 walk through gate and a larger gate that can be driven through. It will be attached to another fence on either side (one is sturdy, and another well is not so sturdy and I will probably replace it within a year). I think I remember reading before that I should put gravel at the bottom of the hole of each post to allow water to drain from the post.
I want to make sure the new fence I put up is done right, and that it will hold over time.
So how deep should I set the metal posts, and if I should put gravel at the bottom of the hole, how much?
Best Answer
How tall are your posts to start with? A 6 foot above ground post should have at least 2 feet in the ground in your area. I would be setting them in concrete so you have a good solid base and good ballast. A metal post in concrete won't rust as long as you dome the top of the concrete so water runs away from the post.
I'll share a clever trick that works well and is very fast. After digging your hole for the post, set one or two bricks in the bottom of the hole to set your post on. You will of course have to adjust for height and plumb the post. Then simply pour an 80 pound bag of Sacrete premixed concrete mix around the post dry, right from the bag. Now just pour apx 2 gallons of water on top of the mix and leave it alone for 24 hours. You will have a solid concrete base for your posts without having to mix concrete. Mixing concrete is good, even better, but this little trick is fast and easy.