Installing Fence Posts the Right Way

Everyone might think they know how to put a wood post in the ground, but installing fence posts properly is about a lot more than simply ramming obelisks into the floor. There are various things that can affect how setting up your fence posts might play out and to ensure that your fence and its posts will stand the test of time, it’s worth clueing yourself up on how to install wood fence posts and concrete fence posts the right way.

We’re going to break down the steps you should take when it comes to 4x4 fence post installation, whether setting directly into soil, using gravel, or securing with concrete. There are differing schools of thought on which method is the best, but that’s not we’re here for, this article is about teaching you the techniques you need to know.

Note that every step in this guide should be repeated for every post you intend to build your fence from, granted you measure the gaps between post spots and align them carefully.

Installing Directly Into Soil / Setting with Gravel

If your space features less dense soil, you can install your fence directly into the ground. While this isn’t the most stable way to do so and can take a fairly long time, it’s cheaper than setting fence posts with concrete, requiring fewer tools and elements.

If you follow these steps, with some alterations, they’ll also apply to setting in fence posts with gravel. These are each considered to be generally, the least costly ways of securing fence posts.

Step 1: Choose Sturdy, Straight Posts

This step applies to each and every method in this article, but always remember to source high-quality, straight posts. Strong redwood, black locust, or cedar fence posts will do a great job, while you can also choose an appropriate pressure-treated wood option, just make sure to vet the supplier to avoid getting burned.

Step 2: Treat the Ends of the Wood

The sawn-off ends of wooden fence posts are highly sensitive to moisture, so it’s worth giving them some treatment, especially in damper climates. You can cut a 45-degree angle into the top end to encourage rain runoff, while both ends should be treated with a brush-on preservative to protect them from moisture.

Step 3A: Dig Your Hole - Soil Only

When setting your posts into soil, dig a hole with a diameter as close to the size of the fence post as possible. There is some debate on how deep fence post holes have to be, with some arguing they should be around half the length of the post and others saying a quarter, so to be safe we advise that you go for around a third. Use a post hole digger for straighter holes.

Step 3B: Dig Your Hole - Gravel Set

If you’re setting fence posts into the soil with the addition of gravel, you want to dig your holes with a slightly wider diameter, so you can fit the gravel in more effectively. You want the diameter of the hole to be around 8 inches long for a standard 4x4 post, so you can easily surround it with the gravel once the post is planted.

Step 4: Lay Some Gravel on the Bottom of the Hole

Even if you don’t plan on using gravel to set your posts in place, you should lay some gravel at the bottom of the hole, to help wick away moisture and improve soil drainage. Simply pour some gravel into the hole, then pack it in so it doesn’t stand too tall with an old piece of wood, broom handle, or something of the sort.

Step 5: Steady Your Post in Place

Once your hole is dug and prepped, it’s time to place in your post, and it’s at this juncture that you could really use an assistant. Have them hold you fence post firmly in place, then use four wooden stakes and two lengths of wire/string to create a brace for the post while you ensure that the post is perfectly vertical with a spirit-level checker.

Step 6: Fill the Hole

Once the post is steadily in place, it’s time to start filling the hole with either soil or gravel, depending on the method you’ve chosen. Make sure to shovel in the gravel or soil a little at a time, only a few inches, tamping it down well to ensure that it’s secure. Make sure to keep checking the straightness of the post with every shovelful.

Step 7: Create a Small Hillock

Once your fence post is well and truly stuck into the ground with either gravel or soil, it’s time to build a small hillock of soil and dirt over the top of the gravel or soil now in the hole. Make sure that this hillock slopes down away from the post in every possible direction, as good drainage will help to prevent rotting.

Installing with Concrete

Now that we understand the principles of how to set fence posts in gravel or soil, let’s take a look at something with a little more security. Setting your posts in concrete is better for areas with higher levels of wind, along with being useful for gated parts of a fence as it can withstand more pressure.

Many of the steps in setting fence posts in concrete are comparable to the steps taken when installing with gravel and soil, so this guide will highlight the differences rather than retreading the same information.

Alternate Step 1: Digging Your Hole

When digging your hole for a concrete set fence post, you need to make it even wider than if you were to set it with gravel, as you need plenty of space for your concrete sleeve to work its magic. For a standard 4x4 post you want the diameter for the hole to be around 12 inches, while the depth should still be around a third of the post, but with an added 6 inches for gravel.

Alternate Step 2: Bracing Your Post

While the stake and wire method is still useful when securing your fence posts into the perfect place, you also need to use a couple of stakes on the inside of the hole, into the gravel that the posts sit on top of. Once these stakes are in place, you can cover them and some of the post in more gravel to keep it even more steadily in place.

Alternate Step 3: Mixing Concrete

Whether you use a rented concrete mixer, mix a DIY mix yourself, or choose to use a quick pre-mixed powder (less reliable and weaker), you need to mix up some concrete. If you’re taking the DIY route, then you’ll need a wheelbarrow, some cement mix, gravel, and sand,

which you can mix together with water to the right consistency using a shovel.

Alternate Step 4: Pouring Concrete

Once your concrete is mixed and ready for use (it should come off the shovel with ease), begin shoveling it into the hole, up to around soil level. Make sure to keep checking the level of the post while you work, as while the concrete’s wet you can make adjustments, but when it dries - game over. With a little excess concrete, create slopes at the bottom much like with the soil.

Alternate Step 5: Sealing the Gaps

Once the concrete has been set (usually taking around 3 days) you simply need to seal the gaps between the post and the concrete with some caulk or an expanding silicone sealant as this will not only help keep it secure but also help with weatherproofing. Once this is done, you’re ready to start making your fence.

Final Thoughts

Now you know how to put in fence posts properly, remember that a careful touch is crucial. Whether installing into gravel, concrete, or soil, and whether planning to create a fully wooden, or concrete post wood fence, attention to detail and meticulous care are key when setting up fence posts. One wrong angle could jeopardize a whole fence operation, so make sure to keep your spirit level handy, work with a partner, and be safe.

Once your fence is set up, why stop there? You can bring a welcome addition of class and style to your fence with some post caps, which will add to the overall visual appeal and value of your outdoor spaces.

For more interesting content on outdoor living, check out the rest of our blog series, and have a great day!