How to Securely Install a Mailbox

By
Kamron Sanders
Kamron Sanders
Kamron Sanders
Kamron Sanders is a home improvement expert and writer with over 15 years of hands-on construction, remodeling, woodworking, home repair, and landscaping experience. He has also written for HGTV. Kamron's expertise ranges from troubleshooting saws and lawnmowers to painting kitchen cabinets.
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Published on 04/22/23
installing a mailbox

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Project Overview
  • Working Time: 1 - 3 hrs
  • Total Time: 1 - 2 days
  • Yield: DIY mounted mailbox
  • Skill Level: Intermediate
  • Estimated Cost: $50 to $150

Installing a mailbox yourself can save you money and get your mailbox back in working order over the weekend. Whether you need to replace a broken mailbox or simply want to boost your curb appeal with a stylish mailbox update, this job is easy for any DIYer to tackle.

While there are a few essential guidelines for mailbox installation, such as height and distance from the road, the process is very straightforward—no handyman is required. Read ahead to learn the proper way to install a mailbox.

Before You Begin

Before you break ground, you must decide what type of mailbox post you're using. The United States Postal Service recommends using either a 4-inch by 4-inch wooden post or a 2-inch-thick metal post. Both of these materials are recommended due to their "yielding" properties, meaning they'll break if hit.

Unyielding materials, such as concrete, heavy metal, or concrete-filled items, should be avoided due to safety concerns. If you don't wish to build a mailbox post, premade mailbox mounting posts are available in a variety of materials and styles from various retailers.

Altering the Mailbox Installation Instructions

While installing a mailbox is a simple task for many DIYers, the steps may vary depending on your specific mailbox and post. There are many different types on the market and you should always consult the manufacturer's instructions for proper installation methods.

What You'll Need

Equipment / Tools

  • Measuring tape
  • Post-hole digger
  • Level
  • Bucket
  • Shovel

Materials

  • Mailbox
  • Mailbox post
  • 1 50 lb. Bag Quick-setting concrete

Instructions

How to Install a Mailbox

Follow the steps below to mount a mailbox that's firmly set in the ground and stays straight for years to come.

  1. Get Rough Measurements for Hole

    Decide approximately where you want your mailbox hole to be. Then, with the mailbox mounted to the post, lay it over the hole to see how far the front of the mailbox will be from the curb. Move it forward or back until the front of the mailbox rests 6 to 8 inches from the curb, then mark the ground where the post is currently positioned.

  2. Decide Hole Depth

    Place the bottom of the post on top of the marked spot on the ground and measure from the ground to the bottom of the mailbox. Once in the ground, the mailbox should sit 41 to 45 inches from the ground.

    To determine your hole depth, subtract 41 to 45 inches from the measurement from the ground to the bottom of the mailbox.

    Tip

    According to USPS, the depth of your mailbox hole should be no more than 24 inches. If the number you arrive at for your hole's depth is more than 24 inches, you will need to shorten the length of your post.

  3. Dig the Hole

    Use post-hole diggers to dig the hole for your mailbox post. Because the space around the post will be filled with concrete, refrain from making the hole too wide to save on materials.

  4. Tip

    For easy cleanup, place your dirt onto a tarp or thick cardboard as you remove it from the hole.

  5. Place the Post Into the Hole

    Lower the mailbox post into the hole until it rests on the bottom. Double check your measurements to make sure the bottom of the mailbox sits 41 to 45 inches from the ground and add or remove dirt if necessary.

  6. Fill Hole With Concrete

    Mix the concrete according to the manufacturer's instructions, then fill the void around the mailbox post, stopping approximately 3 inches short of the ground level. Wiggle the post back and forth several times to ensure there are no air pockets, then straighten the post until it sits plumb.

  7. Check and Adjust the Post

    Place a level on the front and side to ensure that the post is plumb before the concrete hardens. Adjust if necessary.

    Tip

    To guarantee that your post stays plumb while the concrete hardens, you can attach one or two horizontal support legs until the concrete dries.


    For wood posts, simply screw the supports into the wood. For metal posts, you can attach the wooden support legs with 1/2-inch galvanized hanger strap or even heavy-duty zip ties.

  8. Let Concrete Harden

    Let the concrete totally harden according to the manufacturer's instructions before moving forward.

  9. Fill the Top of the Hole

    Fill the remaining 3 inches of the hole with top soil, then plant grass or landscape around the post.

  10. Mount Accessories

    Mount house numbers, mailboxes, and any other mailbox accessories to the post.

How to Keep Your Mailbox and Post in Good Condition

Inspect your mailbox and mailbox post on an annual basis. If you see any rot, rust, or other deterioration, address it before it becomes a bigger problem. If the deterioration is already causing a problem, consider replacing the components.

FAQ
  • Should a mailbox post be set in concrete?

    There is no guideline in place specifying that a mailbox post must be placed in concrete. However, many installers opt to set the mailbox post in concrete, as it makes it easy to achieve a firm, stronghold in the ground with minimal effort.

  • How deep should I dig my mailbox post?

    The United States Postal Service specifies that a mailbox post shouldn't be buried more than 24 inches deep. However, you should make sure the post is deep enough to have a strong hold in the ground.

  • How far off the ground should a mailbox be?

    The United States Postal Service specifies that a mailbox should sit between 41 and 45 inches from the ground. This allows the mail carrier to easily reach the mailbox from their vehicle.