How to Fix a Mailbox

Co-authored by wikiHow Staff

Last Updated: October 27, 2021 References

Whether due to a snow plow, vandals, or just normal wear and tear, a broken mailbox is frustrating. Fortunately, we have all the tips you need to fix it yourself!

Method 1

Method 1 of 3:

Reattaching the Mailbox to the Post

1
Assess the damage to your mailbox and post. If the post is still standing, wiggle it to see if it’s stable. If it’s sturdy, and if the mailbox is intact, you might just need to screw the box back onto the post.^{[1]
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- Check the top of the post and bottom of the mailbox. If the metal bracket that connected them is damaged, you’ll need to replace it.
- If the post wobbles, you’ll need to remove it and install a new one. If your post is made of metal and there aren’t holes for screws at the top, your best option is to get a new post. Otherwise, you’d have to solder the mailbox to the post.
2
Sand or saw off any damaged wood if you’re salvaging the post. Screws that connected the post and mailbox might have caused wood at the top of the post to splinter. If necessary, use 40- to 60-grit sandpaper to smooth the top of the post. For more significant damage, you might need to saw off the damaged top.
- In the United States, the US Post Office (USPS) sets guidelines for mailbox height. If you need to remove some of the top, make sure the bottom of the mailbox opening will stand 41 to 45 inches (100 to 110 cm) off of the ground.^{[2]
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- For locations outside of the US, check the website of your national mail service for mailbox guidelines.
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3
Purchase a mounting bracket that fits your mailbox. If the mounting bracket is warped or broken, you’ll need to replace it. Universal mounting brackets are available online and at home improvement stores. If you know your mailbox’s manufacturer, you could also order a bracket specifically designed for it.^{[3]
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- Most store-bought mailboxes are secured to the post by a mounting bracket. Mailboxes typically have pre-drilled holes along the sides or on the bottom. A universal bracket has an assortment of holes that line up with a variety of designs.
- You might need to use a piece of 1x6 wood to support your mailbox if it doesn’t use a bracket or you can’t find one that fits it.
4
Purchase galvanized deck screws to install the bracket. If your bracket kit doesn’t include screws, purchase (4) 1 ³⁄₄ inch (4.4 cm) and (4) ³⁄₄ inch (1.9 cm) galvanized deck screws.^{[4]
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- Some kits include flimsy hardware, so it’s wise to buy screws separately even if the kit provided some.
5
Pre-drill holes into the top of the post. Place the bracket on the post, and mark where the pre-drilled holes line up on the top of the post. Set the bracket aside, then use a power drill to pre-drill holes into the top of the post. Fit your drill with a bit that's slightly smaller than your screws' thread diameter.^{[5]
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- In general, the bit should match the screws' shaft diameter, which is smaller than the thread diameter. For a list of screw sizes and corresponding bits, see http://faculty.etsu.edu/hemphill/tap_drill.htm.
- If there are already holes in the top of the post from the old mounting bracket, drill new holes. Old holes might have been stripped when the box was knocked off, or they might not fit your new screws. Shift the bracket’s position on top of the post to avoid the old holes.
6
Screw the bracket onto the post. Line up the bracket’s holes with the holes you pre-drilled into the post. Drive the 1 ³⁄₄ inch (4.4 cm) screws through the holes to secure the bracket to the post.^{[6]
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7
Secure the mailbox to the bracket. Locate the pre-drilled holes on your mailbox. Line them up with the bracket, then use the ³⁄₄ inch (1.9 cm) screws to secure the mailbox to the bracket.^{[7]
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- For most models, the holes are lined up along the bottom of the sides. They might also be located on the underside of the mailbox. A universal bracket will have pre-drilled holes to fit both of these locations.
8
Use a 1x6 piece of wood if you can’t find a mounting bracket. If you can’t use a bracket, cut a piece of 1x6 pressure-treated wood to fit inside the mailbox’s skirt. The sides of the box extend about ¹⁄₂ to 1 inch (1.3 to 2.5 cm) past the bottom, and this depressed space on the underside is the skirt.^{[8]
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- Pre-drill holes into the board that correspond with the holes in the post and mailbox.
- Align the holes you pre-drilled into the board with those pre-drilled into the post. Secure the 1x6 board to the post with a pair of 1 ³⁄₄ inch (4.4 cm) galvanized deck screws.
- Next, drive ³⁄₄ inch (1.9 cm) screws through the mailbox’s pre-drilled holes to attach it to the wood support.^{[9]
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Method 2

Method 2 of 3:

Installing a New Post without Concrete

1
Remove the old post, if necessary. If the old post isn’t salvageable, dig it out of the ground with a shovel. If it’s not embedded in concrete, digging out the post will be relatively quick and easy.^{[10]
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- Pulling out a concrete block is a tougher job. You could dig around the perimeter of the block and pull it out but, because of the block’s weight, you’ll need 1 to 2 people to help.
- You could also saw the post off at ground level, leave the concrete in the ground, and choose another spot for your mailbox. If the old concrete is exposed, cover it with soil or gravel.
2
Purchase a new mailbox post at a home improvement store. Choose a post made of a material that won’t rot, such as pressure-treated wood or PVC. Basic posts are simple lengths of 4x4 wood or PVC. ^{[11]
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- For more elaborate, decorative posts, you need to attach the base to a standard 4x4. You then bury the 4x4 in the ground or embed it in concrete. The 4x4 is usually sold separately.
- Don’t use posts made of unyielding materials, such as concrete or solid metal, as these might be illegal in your jurisdiction. The USPS recommends a 4x4 pressure-treated wood or PVC support. You may also use a 2x2 hollow aluminum or steel pipe.
3
Dig a hole for the new post that complies with USPS guidelines. Make the hole around 1 foot (30 cm) in diameter. You’ll need a little room to add soil back after you’ve placed the post in the hole. Measure your post to determine how deep the hole needs to be in order to comply with USPS standards.^{[12]
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- The USPS recommends burying a mailbox post up to 2 feet (61 cm) deep. The base of the mailbox’s opening must sit 41 to 45 inches (100 to 110 cm) above ground level. The opening should be 6 to 8 inches (15 to 20 cm) from the curb, so position the hole accordingly.^{[13]
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- For example, if your post is 60 inches (1.5 m) and the mailbox attaches directly to its top, dig a hole that’s 19 to 24 inches (48 to 61 cm) deep. If the mailbox will sit on a support arm, measure 41 to 45 inches (100 to 110 cm) from the arm instead of from the top of the post.
- You might be able to reuse the old post’s hole as long as your new post is a similar size. Otherwise, you’ll need to make the hole deeper or more shallow to accommodate the new post.
- Check with your national mail service's guidelines if you live outside of the US.
4
Insert the post into the hole and make sure it’s level. Set the post into the hole, and use a bubble level to make sure it’s plumb. Throughout the process of filling the hole, check for levelness periodically, and make adjustments as necessary.^{[14]
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- Double check your product's instructions to see which side of the post should be inserted into the ground.
5
Fill the hole about halfway with dirt. Try to keep the post in place as you shovel dirt back into the hole, or have a helper hold it to keep it level. Check for levelness after you’ve filled the hole about halfway.^{[15]
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6
Tamp the dirt, add more dirt, then tamp the ground again. Use a hand tamper, sledgehammer, or a long piece of scrap wood to pack the dirt tightly around the post. Once the dirt is packed, add another 6 to 12 inches (15 to 30 cm), then tamp that layer. Repeat until you’ve filled in and packed the hole.^{[16]
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- Remember to check the post for levelness and make adjustments as you fill and tamp the hole.
7
Attach the mounting bracket and mailbox to the post. After you’ve buried the post, screw on the mounting bracket. Then screw the mailbox onto the mounting bracket.^{[17]
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- If you’re reusing your old mailbox, you can find universal mounting brackets online and at hardware stores. Line up the bracket’s pre-drilled holes with the holes pre-drilled into the mailbox and post. Use 1 ³⁄₄ inch (4.4 cm) galvanized deck screws to secure the bracket to the post, and ³⁄₄ inch (1.9 cm) to attach the box to the bracket.
- If you bought a new post and mailbox together, follow the manufacturer’s installation instructions.

Method 3

Method 3 of 3:

Securing a Post with Concrete

1
Make sure your local government and HOA allow concrete supports. Some cities and homeowners associations prohibit the use of concrete to support mailbox posts. Before starting your project, check your city government's website or call a local buildings inspector. If applicable, check with your HOA, too.^{[18]
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2
Purchase a new weather-resistant post. Find a pressure-treated wood, PVC, or hollow metal mailbox post online or at a home improvement store. Simple posts are just 5 to 7 foot (1.5 to 2.1 m) lengths of 4x4 wood or PVC.^{[19]
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- If you go with a more elaborate, decorative option, you’ll need to attach the base to a standard 4x4, then mount the 4x4 in the ground. Keep in mind the 4x4 is usually sold separately.
- Avoid posts made of unyielding materials, such as concrete or solid metal, which could be illegal in your jurisdiction.
3
Dig a hole for the new post that complies with USPS guidelines. The hole should be around 1 foot (30 cm) in diameter so you’ll have room to add the concrete after placing the post in the hole. Measure the post to find how deep you should dig in order to comply with USPS guidelines.^{[20]
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- The USPS advises burying a mailbox post up to 2 feet (61 cm) deep. The bottom of the mailbox’s opening must sit 41 to 45 inches (100 to 110 cm) above ground level. Additionally, the opening should be 6 to 8 inches (15 to 20 cm) from the curb.^{[21]
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- Check with your national mail service's guidelines if you live outside of the US.
4
Add 6 inches (15 cm) of gravel to the hole. Add the layer of gravel after digging the hole to the correct depth. Adding gravel or small stones before pouring concrete will help water drain properly.^{[22]
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5
Mix the concrete according to the manufacturer’s instructions. Purchase a concrete mix at your local hardware store. Pour it into a wheelbarrow or concrete tray, add water as directed, then mix it until it’s about as thick as peanut butter. The precise ratios vary by manufacturer, so use the amount of water listed in the instructions.^{[23]
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- Purchase 2 50 pound (23 kg) bags of concrete mix to fill a 10 inch (25 cm) diameter hole that’s 2 feet (61 cm) deep.^{[24]
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6
Set the post in the hole and ensure it’s level. Insert the post into the hole, and use a bubble level to make sure it’s plumb. Check for levelness periodically as you fill the hole with concrete, and make minor adjustments as necessary.^{[25]
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- You could also have a helper hold the post in place and check for levelness as you pour the concrete.
7
Add concrete to within 3 to 4 inches (7.6 to 10.2 cm) of ground level. Use a shovel or trowel to fill the hole with concrete. Instead of filling the hole all the way to the top, leave a little room between the top of the concrete and ground level.^{[26]
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- If you leave a little room, you can fill in the space with dirt or gravel after the concrete sets. Dirt or gravel will look better than bare concrete.^{[27]
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8
Allow the concrete to set as directed. The set time depends on your product, and could be from 30 minutes to several hours. Be sure to check the post for levelness before the concrete begins to set.^{[28]
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9
Cover the concrete with dirt or gravel after it has set. After allowing the concrete to set as directed, disguise it with a layer of dirt or gravel. Fill in the 3 to 4 inches (7.6 to 10.2 cm) of space you left between the top of the concrete and ground level.^{[29]
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10
Attach the mailbox and mounting bracket. Line up the mounting bracket’s pre-drilled holes with the post’s holes, then secure them with 1 ³⁄₄ inch (4.4 cm) galvanized deck screws. Align the bracket with the mailbox, and drive ³⁄₄ inch (1.9 cm) screws through their pre-drilled holes to complete installation.^{[30]
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- If you’re reusing your old mailbox, purchase a universal mounting bracket online or at a hardware store.