Installing fence posts can be an intimidating task for many folks. The thought of mixing and pouring concrete to anchor the posts can easily scare away the average DIYer. Luckily, there are several functional alternatives that will allow you to install a fence post without concrete.
Fence posts can be anchored with gravel, resulting in surprisingly strong anchors that also drain away moisture to prevent water damage. Posts can also be secured using fence post spikes – which are specially made metal anchoring spikes that don’t require digging to install.
Let’s take a look at these ways to install a fence post without concrete in more detail, so you’ll be prepared to set your own fence posts in no time!
How to Install a Fence Post with Gravel
Fence posts installed in concrete are notorious for falling victim to water damage over time.
You’d think the concrete would lock the post in place and prevent any moisture from getting in, but the opposite is often the case. The concrete fractures and warps over time, opening small cracks around the base of the post that allows water to seep in. As concrete doesn’t drain quickly, this moisture pools around the fence post and leads to rot setting in below the ground.
Fence posts set in gravel solve this issue by forming fast-draining anchors that mimic the strength and rigidity of concrete.
You might think setting fence posts in gravel would result in a flimsy hold, however as long as you make sure your hole is deep enough and you properly tamp down the gravel and dirt, the result is a rock-solid fence post.
Tools & Materials
Here’s the step-by-step process in detail:
Step 1: Dig the Hole
The first step is selecting your fence post location and digging your hole. Use your tarp or heavy-duty garbage bag to pile the dug-up soil onto. You’ll need to save some of this soil for later on.
The rule of thumb for hole depth is about a third of the overall post length should be below ground. So for a 7-foot fence post, a 2 ½ foot deep hole will be more than sufficient. You can also go deeper (up to half of the overall post length), but this is unnecessary for most applications.
As far as hole width goes, aim for 2 to 3 times the width of the fence post.
Step 2: Fill the Base with Gravel
Once your hole is dug, you’ll want to fill the base of the hole with 4 inches of gravel. This assists with draining away water and ensures the bottom of your fence post is not sitting on wet soil.
Loose gravel with both small and larger pieces works best, as it compacts better than larger, evenly sized pieces.
Step 3: Position your Fence Post
This step is important to get right. If you don’t position your fence post correctly now, you won’t be able to reposition it later without digging up the entire thing and starting over.
Use a level to ensure your fence post is plumb in the ground. You might need an extra hand holding the post in place as you add more gravel, or you can build a makeshift frame to hold it in place.
Once your post is positioned as you want it, add another 2 inches of gravel to the hole. Tamp the gravel flat with the flat end of a digging bar, a shorter section of fence post, a brick, or anything else you have on hand.
Step 4: Filling Hole & Tamping
Now your fence post is effectively set in place, so you just need to fill the hole and tamp the material flat. Tamping everything flat as you go is important, as this is what creates tightly compacted material that will hold the post in place similar to the way concrete does.
Fill the hole with about 4 inches of gravel at a time, and then tamp flat. Repeat the process until you are about 6 inches from the ground.
At this point you’ll want to switch to the soil you dug up earlier. If the soil in your area is rich in clay (as mine is), then this will work as a sort of a water barrier to prevent moisture from penetrating your post hole. If your soil is sandy, then you’ll want to find denser soil to seal off the top.
Fill the rest of your hole up with the previously dug soil, and tamp it down thoroughly until it has no give left.
Installing a fencepost in gravel offers a number of advantages over using concrete. Beyond the ones mentioned above, gravel fence posts tend to shift rather than snap under extreme stress. This means you’ll be able to reset the post to plumb after heavy winds.
Contrast that with fenceposts set in concrete, which can break in heavy winds, leaving a broken post that must be extracted and replaced.
Gravel fence posts are also much easier to remove later on than their concrete counterparts. If there’s any chance you’ll want to remove the fence at some point, then gravel is the way to go.
Lastly, you’ll want to consider your soil type when putting in fence posts. If you live in an area with exceedingly sandy soil, then you’ll likely need to use a method other than gravel for anchoring your posts.
Installing a Fence Post with Post Spikes
Another common method of anchoring fence posts is by using fence post spikes.
These spikes are essentially 2 to 3-foot long metal spikes that you drive into the ground with a sledgehammer. Above the spike is a metal sleeve fitted to drop a fencepost in, which is secured with a couple of lag screws and a socket wrench.
Many anchor spikes are made from galvanized steel, which protects your wood fence post from damage and extends the life of the fence.
The main advantages of post anchor spikes are their ease of installation, their low cost, and their versatility. Post anchor spikes are easy to remove and re-adjust, so if you make a mistake during installation you can use a long pry bar to rip it out and start over again.
Post anchor spikes also work well for temporary fencing installations, or for apartment dwellers who aren’t able to pour concrete.
Here’s how to install a fence post without concrete using a post anchor spike:
Step 1: Place the Spike and Hammer in Place
First, you’ll want to position your spike and push it as far into place using your bodyweight as possible. Then, take a short 1-foot section of the fence post and place it inside the metal sleeve.
Then, begin hammering the short section of the fence post into the ground with your sledgehammer. You’ll want to keep a level nearby to ensure the post is plumb every few sledgehammer strikes.
Step 2: Install Fence Post
Once you’ve driven the post spike into position, you’ll need to replace the short section of fence post used to drive the spike with the real one.
Then you’ll want to use a level to double-check the post is plumb, and attach the post to the anchor spike with lag screws/bolts.