With mail theft on the rise, high security mailboxes have become increasingly popular. Fort Knox Mailboxes are the leader in mail and package security. But installing one of these beasts isn’t as simple (or light weight) as plopping up a tin can on wood post. This Fort Knox Mailbox installation guide thoroughly explains how to install your mailbox securely, while meeting USPS guidelines.
1. Gather the Necessary Tools
- Level
- ⅝ Wrench + Fort Knox Mailbox Hardware (4 3/8"-16 x 1" Carriage Bolts, Lock Washers, and Acorn Nuts. If you have an M1LT Post, you’ll need 3/8"-16 x 3/4" Carriage Bolts)
- 2 Buckets
- Digging Bar
- Post Hole Digger
- Tape Measure
- Small Shovel
- Landscape Rake
- Broom
- Two Bags of Concrete Mix (it doesn’t normally take both bags)
- Water (roughly 4 liters, about 2 liters per 60 pound bag)
2. Review the USPS Requirements
Your mailbox placement needs to meet the following USPS requirements (as of July 2024):
Mail Point of Entry: 41″ to 45″ from the road surface
Keep in mind, on a Fort Knox Mailbox, the mail’s point of entry is above the secure storage compartment. This is different from traditional mailboxes with a single hinge door.
Placement: 6″ to 8″ back from the curb
If you do not have a curb, you’ll need to contact your local postmaster for guidance on where to install your mailbox.
Label: Put your house or apartment number on the mailbox.
3. Call Before You Dig — Then Dig a Hole
In order to avoid hitting any utilities when you’re digging, always call before you dig. In Washington, the Utility Notification Center is open 24 hours a day, 7 days a week — 1-800-424-5555 (or 811).
Once you’ve ensured you won’t be digging into a waterline, powerline or worse, sewer line, start digging your hole. In an ideal situation, you’ll use your digging bar to break up the dirt and then use your Post Hole Digger to create a hole deep enough to meet the USPS guidelines.
Normally, a Fort Knox Mailbox Post needs to be installed 22″ to 24″ into the ground. As you’re digging, you’ll want to measure the hole to ensure it’s deep enough, but not too deep.
Replacing a Previously Installed Mailbox
If you are replacing a previously installed mailbox, you may not be able to use your Post Hole Digger. And what’s worse, you can get into a hole with excess concrete. In cases such as this, you end up with a wide gaping hole. Trying to set a pole in such a large space can take an excessive amount of time.
The fix is to use some of the concrete and dirt you removed to create a smaller space in which you will pour your concrete.
4. Prep the Hole & Set the Mailbox
Put a small amount of concrete in the base of the hole. This will act as a foundation in which you will set the post.
Each Fort Knox Mailbox post has a seam on one side. You’ll want to find this seam and orient the post so it’s facing away from the road. Place the post with the falange up.
5. Measure Placement
Measure from the center of your bolt down pattern to the very front of your mailbox. Then measure from the center of the post falange to the curb. You’ll want this second length to be 6″ to 8″ longer than the initial length.
6. Fill the Hole with Dry Concrete & Do Initial Level
Add dry concrete mix around the hole and then level your post. It doesn’t have to be exact, as you will be mixing the concrete and will need to re-level the post.
For a Fort Knox Mailbox, you want the post to be level side to side and about a ¼ bubble lean forward.
Why a ¼ Bubble Lean Forward?
Fort Knox Mailboxes are solid on the bottom. With a hard rain, they can fill with water. So the slight lean helps that drain out.
7. Mix Your Concrete
Add water to your dry concrete and mix it until a thick sludge forms. Then before your concrete solidifies, re-check the level on your post.
Why Mix Concrete in the Hole?
There are several different ways to do concrete. Initially Gary, our Fort Knox Mailbox installation expert, would bring a wheelbarrow out to mix the concrete. Then he moved on to a Rubbermaid bucket. But after a fence was installed at his house, he saw the installation crew mixing the concrete in the hole. His fence doesn’t budge and so he started doing the same with mailbox installs.
The beauty of mixing it in the hole is two fold. First, you can gradually add the water so as to avoid over saturating the concrete mix and needing to wait days for the concrete to set. Second, it really cuts down on cleanup.
Concrete Alternatives
On residential streets where traffic is at a minimum, there is the space and time to let concrete set. On busier streets, you may prefer using pea gravel. Given the depth of the hole, the gravel will be plenty strong to keep the post in place, while not requiring time to dry.
8. Clean Up Your Space
Cover the concrete mixture with dirt and use the landscape rake and broom to sweep up any debris that may have been scattered around the surrounding surface.
9. Bolt On Your Fort Knox Mailbox
Each Fort Knox Mailbox comes with the required bolts to secure your mailbox to your Fort Knox Mailbox Post, including 4 of the following:
- Carriage Bolt
- Lock Washer
- Acorn Nut
The Carriage Bolt comes in from the underside of the mailbox’s exterior, running through the hole on the post and the corresponding hole on the mailbox. Inside the mailbox, slide the Lock Washer onto the bolt, followed by the Acorn Nut.
You’ll want to initially hand tighten each bolt. Once all four are in place, you can use your ⅝ wrench to tighten them.
10. Write Down Your Key Number
Now that your mailbox is installed, you want to write down your key number in a secure location. The keys are from Medeco and have special key numbers that prevent them from being copied. If you lose your key, the only way to get a new key issue is with your key number.
Fort Knox Mailbox Installation FAQ
Do You Have to Install a Fort Knox Mailbox on a Ford Knox Mailbox Post?
No. It’s a free country. You can install your Fort Knox Mailbox any way you please — including on a wood post or set within a brick structure. That being said, we strongly recommend purchasing the Fort Knox Mailbox post designed for your mailbox. When properly installed, we’ve seen these mailboxes withstand harsh beatings ranging from being hit by car to slammed with a sledge hammer without falling off.
Can I Install a Fort Knox Mailbox Without Digging a Hole?
You sure can! The Fort Knox Mailbox Post (officially named the M1-LT Steel Post) comes with both an in-ground design and a surface mount design for bolting to cement. These posts would be specialty items.
Can I Install Multiple Fort Knox Mailboxes Together?
Definitely. In addition to the stand alone posts, Fort Knox has posts designed for clusters of 2-3, bigger clusters, and 1/4″ Cluster Box Units, which can house both personal mail slots and larger package compartments. These posts are specialty items. Please call the store to request them.
Do I Have to Install My Own Fort Knox Mailbox?
Definitely not! If you live in the greater Seattle area, Spokane, or Coeur d'Alene our Gary Reynolds is our go-to Fort Knox Mailbox Installation expert. He’s installed hundreds of these badboys and can quickly and easily help you out.