How to Install a Mailbox Post Without Concrete (Simple Alternatives to Consider) (2024)

Not too long ago, I came outside to get my mail and found that my mailbox had been involved in a car accident. I was utterly confused because I found a piece of broken headlight next to my mailbox and knew someone had driven into it, breaking the post in half.

I needed to replace the post, but I didn’t want to use concrete, and I wondered how I could install the mailbox post without using concrete.

There are many innovative ways to install a mailbox post without digging a hole and using concrete. You can buy ground anchors online made from galvanized steel. They have a corkscrew bottom that screws into the ground and a steel bracket fastened above the bottom that attaches to the post.

I didn’t want the hassle of digging a 3-foot hole or using concrete, and I wondered if you could install a mailbox post without using concrete. I went to a few different hardware stores and did a bunch of research, and the information I found was very helpful.

I will discuss what I found in this post.

Installing a Mailbox Post Without Concrete

All of us know how important curb appeal is when you want to sell your home or if you just want your home to be well looked after and look inviting. Nothing can mess up your curb appeal more than a broken mailbox post.

This section of the post will look at all the new and innovative ways to replace a mailbox post or install a post where there has never been one in this section.

Using Ground Anchors to Install a Mailbox Post

One innovative way to install a mailbox post without concrete is to use ground anchors. You can find these anchors online or at hardware stores, and they cost less than $35 each.

They have long corkscrew bottoms that look similar to the bottom of a screw, and they have a steel bracket attached on top of the corkscrew section to which you attach the post.

These ground anchors are easy to use and make a great DIY project. When using the ground anchors to install your mailbox post, it works best with a 4 x 4 wood post. Using this method in a DIY project will be more cost-effective than other methods. These anchors are over two feet long and make a sturdy foundation for your mailbox.

It’s a great alternative for places where you can’t dig where there might be tree roots or if you need to install the mailbox in the winter months, its’s easy as you don’t need to wait for the frozen ground to defrost for you to dig a hole. You can easily screw the anchor into the frozen ground.

These ground anchors are very user-friendly. All you need to do is screw the ground anchor into the ground. You get a 20-inch crossbar included in the kit that you use as leverage when screwing the anchor into the ground.

After you have screwed the ground anchor into the ground, you use five lag bolts to attach the post to the bracket. There are pre-drilled holes in the bracket, and the five lag bolts are included in the kit with the 20-inch crossbar.

Pros and Cons of a Ground Anchor to Install a Mailbox Post

When you are installing a mailbox post and looking at different methods that don’t include using concrete, you need to look at all the advantages and disadvantages of each method so you can make an informed decision.

Pros of Using a Ground Anchor Instead of Concrete

Using a ground anchor to install your mailbox has many advantages that we will discuss in this section:

Ease of Installation

Using a ground anchor is an easy DIY project that you can tackle and finish in one afternoon because you have most of the right components in the kit. You get the ground anchor, the 20-inch crossbar, and the five lag bolts you need to secure the post to the ground anchor.

The only other part you need to buy is a post. You only need to screw the bottom part into the ground using the crossbar to get leverage and then fasten the post to the bracket saddle using the five lag bolts that are in the kit, and it’s that easy.

You Don’t Need to Dig a Hole

One of the best pros of using the ground anchor is that you don’t need to dig a 2-3 foot hole where the post is supposed to go. The ground anchor is screwed directly into the ground, and you don’t have to dig down even an inch.

The way the ground anchor is designed (like a screw) means the pointed tip makes it easy to get the anchor as you only twist the ground anchor in a corkscrew motion to get it into the ground, and you won’t need to dig for a place to put it.

The other reason why digging a hole might be a major issue is the cables, pipes, other utility lines, and tree roots might get damaged if you dig a hole for the post and accidentally hit one of these lines, cables, or utilities.

You Don’t Need to Use Any Adhesives Like Concrete

Not everyone loves the idea of spending an entire weekend installing a mailbox post and spending more money than is necessary. Concrete takes at least 24-hours to dry (if not longer) before you can finish your project, and then wait, time, and expenses make using the anchor worth it.

The ground anchor relies entirely on the thick galvanized 2 feet long corkscrew bottom that is driven into the ground for support. Because you don’t need to dig a hole in the ground, the ground also acts as a stabilizer as the surface is only broken where the ground anchor is driven in.

The Mailbox Post Won’t Rot As Quickly

Most mailbox posts are made from thick wood and as it sits on the ground surrounded to a point by concrete, but if it is partially buried in concrete and the rest comes into direct contact with the moist ground, the wood would certainly rot easier over time.

The ground anchor all but eliminates the mailbox bending and rotting due to moisture issues. To avoid wet weather from causing the same harm, you should use pressure-treated and kiln-dried posts. That way, you won’t need to worry about mildew or mold buildup or the mailbox post decaying too quickly as it doesn’t come in direct contact with the ground.

Cons of Using a Ground Anchor Instead of Concrete

While using ground anchors to install a mailbox post is easy, quick, and cheap, there are a few cons to using this method as well.

Its Sturdiness Is in Question

While many people have given this product great reviews, a few people have said that the quality of the ground anchor they bought was not up to scratch, and the anchor was not as sturdy as they thought.

Severe Weather Might Be a Problem

The other issue that there might be with using ground anchors is that if there is severe rainfall and the ground gets too saturated with rainwater, the anchor might come loose. Because the ground helps act as a support structure for the ground anchor, if the ground becomes unstable as the rain causes it to be muddy, the anchor might sag or come loose.

Using Expanding Foam to Install Mailbox Post

One of the other ways to install a mailbox post is to use expanding foam. Over the years, expanding foam has become a popular alternative to use instead of concrete because of its benefits, durability, and user-friendliness.

Over time the expanding foam manufacturers have created a type of expanding foam that has been specially made to install mailbox and fence posts. The SIKA® POSTFIX YIELD is the best example of this. The way to install the mailbox post is as follows;

1. First, you dig a hole 2-3 meters deep, ensuring the hole is bigger on all sides than the post. Ensure where the water, gas, and other utility lines are before you dig the hole.
2. Then you put the post into the ground, making sure to level it out.
3. Now mix the SIKA POSTFIX in the bag provided for no more than 20 seconds.
4. Lastly, pour the expanding foam into the hole, making sure to coat all sides of the post, so it adheres properly.
5. Keep the post still and in place for at least 3 minutes with a bracing device (1×4 strapping) or manually.
6. Allow the foam to cure for two hours and attach your mailbox to the post.

Expanding foam works similar to the way concrete works, but it takes away some of the hassles of dealing with concrete. Concrete tends to absorb water which will cause the post to expand and retract and may lead to the concrete cracking and damage to the wooden post in the process.

Pros and Cons of Using Expanding Foal Instead of Concrete

There are pros and cons to both of the methods we discuss in this post so you can make the best decision possible for your needs. Here are the pros and cons of using expanding foam as an alternative to concrete when installing a mailbox post.

Pros of Using Expanding Foam

Expanding foam is widely used in many forms, and there are formulas made specifically for certain types of jobs. Here are some pros to using expanding foam instead of concrete:

It’s Easy to Use

Using expanding foam is very easy to use as all you need to do is mix the foam for 20 seconds, pour it into the hole, keep the post still for three minutes and then let it cure for two hours. It takes the hassle of using concrete out of the picture.

It’s Inexpensive, and You Use Less

Using expanding foam is not only easy, but it’s less expensive than using concrete. You don’t have to use as much because the foam expands, meaning you can install the post using one bag.

It’s Water-Resistant

The one great feature of the expanding foam is it’s water-resistant. Water-resistance is very important as it will help the wooden post last much longer. It won’t be directly exposed to the moist ground because the expanding foam acts as a barrier between the ground and the post.

It’s Fast Curing

Unlike concrete, which can take up to two days to cure, the expanding foam only takes a few hours, and your post will be cured, and you can attach your mailbox, and you’re done.

You Don’t Need to Add Water

It’s less time-consuming when using expanding foam as you don’t need to add water; you just mix the ingredients they provide in the bag, mix it up, and our into the hole.

Cons of Using Expanding Foam

When you are using expanding foam, you need to know all the ins and outs of the product. Keeping that in mind, below are the cons of using expanding foam.

Repairs Are Difficult

If there is a problem and you need to make repairs, it won’t be easy as it might crush the foam and damage the backfill. Some brands have a stronger product that can completely replace the concrete that might be better.

Final Thoughts

When you want to install a mailbox post without using concrete, you need to weigh all the different options, their pros, and cons, so you make the best decision for your needs. Many people don’t want to use concrete, and some people are not avid DIYers, so these options will work best for them.

Using either a ground anchor that you screw into the ground and attach the post to the bracket saddle or using expanding foam as a concrete alternative will be two of the best options to install a mailbox post without using concrete. Both options are less expensive, less time-consuming, and easy to use.