How to Set Fence Posts in Concrete

Installing a fence is one of those projects that DIYers believe is much more difficult than it really is so they tend to shy away from the task. This might be because of the perceived scale of the project. An entire backyard is a big space, after all, so it might be the one project the avid DIYer chooses to hire out. But that’s a mistake and I’ll give you 3 reasons why

1)   Hiring a fencing contractor is incredibly expensive.

Even though building a fence adds a lot of utility to your home (especially if  you have pets) and may make your home more attractive to buyers, it does not typically add much, if any, value to a property. For this reason,
it doesn’t make much fiscal sense to invest upwards of $5,000 to hire  someone else to build your fence (including labor). If you need a fence, save money and do it yourself.

2)   As long as you don’t overthink it, fences are very simple in design, not complicated to install, and the materials are generally easy to find.

That sentence just about sums up this point.

3)   Installing a fence is not as laborious or time consuming as you might think. 

In fact, I installed a fence around a quarter acre yard while 8 months pregnant, including digging the post holes. The fence was made out of pressure treated lumber and welded wire with 4×4 posts and 2×4 rails. I’m not suggesting that anyone else attempt this while pregnant, but if I could set fence posts in concrete without being able to see my own toes, I have faith that anyone who can see their toes can too, and here’s how.

STEP 1: Prepare

You may need to have underground utilities staked. Your city probably has a special number to “call before you dig”. Do that. Don’t skip this step based solely on assumptions. It’s free, it’s important, and it only takes 5 minutes. They will send someone out within a week or two to mark important utilities in the area.

You will want to check with your city’s or county’s permitting office to find out if you’ll need a permit or not before you install your fence. If you have social anxiety like I do and hate making calls, just google their website and email them. They can also tell you whether the style of fence you plan on installing abides by local regulations and covenants.

You might need to discuss your fencing plans with your neighbor if you happen to share a fence with them. Make sure they’re on board with your plan and that you won’t have any issues with them related to your new fence later on. They might even be willing to chip in with either labor or cost, especially if your shared fence has seen better days.

STEP 2: Gather Supplies

You will need:

• Post hole digger (you can use a power auger, instead, if you have or need one)
• Shovel
• Bucket or tarp for displaced dirt
• Posts – if you plan to use lumber rather than vinyl or metal posts, it’s recommended that you use ground-contact/pressure-treated 4×4 or larger lumber
• Tape measure
• Fence post level
• Fast-setting concrete mix
• Gravel (optional, but recommended)

STEP 3: Dig

Dig your post hole to a depth that is at least ⅓-½ of the design height of our fence. If you intend for your posts to be 6 ft tall (above-ground), you need to bury an 8-foot post at least 2 feet into the ground. The post hole diameter should be 3 times the width of the post. If you are using a 4”x4” post, your post hole must be at least 12-inch in diameter.  Use the bucket or tarp to collect the displaced dirt in order to not make a muddy mess around your post holes.

STEP 4: Add Gravel to the Base of the Post Hole (Optional but
Recommended)

This step is not required but adding approximately 6 inches of gravel to the base of your post hole will fight compaction and settling over time and provide a solid base for your post and concrete to sit on top of. If you do choose to add gravel, you will want to account for this in your depth measurement and dig 6 inches lower than stated in step 3. After pouring in the gravel and spreading it evenly, tamp it down with the bottom of your post to compact it. You can also use a tamper if you happen to have one that will fit.

STEP 5: Place the Post and Add Concrete

Make sure you have your concrete within reach and attach your fence post level to the top of your post. Place the post upright in your post hole. If working solo, you’ll need to reach for your dry concrete bag and begin pouring the concrete mix into the post hole with one hand while holding the post hole as close to level as you can with the other. Don’t worry, it doesn’t have to be perfectly level yet, just generally upright. Finish filling your post hole completely with concrete, Once filled, pull and push your post into a perfectly level position.

STEP 6: Add Water and Re-Check Level

Using a house out bucket, pour approximately 1 gallon of water evenly onto the dry concrete per 50-pound bag used to fill the post hole. When done, check the post level again and adjust it if necessary.

STEP 7: Allow Concrete to Set and Cure

I generally like to wait overnight for my concrete to set before continuing with building a fence, but quick-setting concrete hardens within 4 hours so, if you’re in a hurry, you can technically resume work on your fence at that point.

And there you have it. Setting fence posts is very simple in both concept and execution.