How to Make & Install a Modern DIY Mailbox

This is one of those projects that was overdue, way overdue! I (Vicki) live in a neighborhood where almost all the mailboxes are brick or stucco, and then there was my falling down, cedar trimmed box. Yikes, I'm really surprised my Homeowners Associated never sent me to notice to replace it!

Since we have no bricklaying skills to build a brick mailbox, we set off to find a style we liked and could build with our skillset. On our weekly COVID-19 lockdown Sunday drives through the neighborhood, we spotted the perfect candidate. We took lots of pictures but resisted the urge to actually get out of the car to take measurements.

Supplies

Materials:

(2) 4 in. x 4 in. x 10 ft. #2 Pressure-Treated Timber (Home Depot)
(6) 1 in. x 4 in. x 8 ft. Ground Contact Pressure-Treated Board (Home Depot)
Sika 33 fl. oz. Fence Post Mix (Home Depot)
Gibraltar Mailboxes Elite Medium Black Galvanized Steel Post-Mount Mailbox (Home Depot)
Veranda 4 in. x 4 in. 7 Lumens Black Plastic Solar Post Cap(Home Depot) Behr Outdoor Paint

Tools:

5 gal. Paint Stick (3-Pack) (Home Depot)
Milwaukee M18 FUEL 18-Volt Lithium-Ion Brushless Cordless Gen II 18-Gauge Brad Nailer (Home Depot)
Makita 15 Amp 10 in. Dual-Bevel Sliding Compound Miter Saw with Laser (Home Depot)
Makita 18-Volt LXT Lithium-Ion Sub-Compact Brushless Cordless Reciprocating Saw (Home Depot)
Flexible Drill Bit Extension (Amazon) Auger Bit (Home Depot)
Titebond III 16 oz. Ultimate Wood Glue (Home Depot)

Step 1: Watch the Video

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Step 2: Purchase Supplies and Make All Cuts

There was a lot of math going on to determine the width and height of the box. It really would have been easier if we could have measured our inspiration box. Basically, the size is based on the length and height of the box itself and the number of slats that are in the inspiration photo. We set up a fence on the miter saw to cut all the slats since we needed so many. This speeds up the cutting as we only had to measure once.

Once all the slats were cut, we painted them. The posts got a coat of black paint.

Cut List

4x4 posts (3-1/2 x 3-1/2 actual)

(1) 41-1/8” (plus 10” to 12” more to put into the ground)
(1) 50-1/2” (plus 10” to 12” more to put into the ground)

4x2 boards (3-1/2 x 3/4 actual)

(21) 19in (20 for two sides, one for base support of mailbox)
(2) 22-1/2in
(4) 4-3/4in

Mailbox dimensions

Height 8-3/4in
Width 6-1/2in
Length 18-7/8in

Step 3: Assemble

We assembled with outdoor wood glue and brad nails. We used large paint sticks to create equal spaces between the horizontal slats.

The mailbox was screwed into place. We used a flexible shaft to screw in the hard-to-reach screws inside the box.

Step 4: Installation

First, we had to remove the old mailbox which was super simple. It fell down really easily as it was old and rotten. I do wish we had taken the time to dig out the old post that broke off at ground level, but since it didn't really impact the installation of the new box, we didn't remove it.

When placing a mailbox, be sure to follow all United States Postal regulations. There are distance and height requirements.

We used a post hole digger to make two holes in which the new posts would sit.

Once we had the depth we wanted, we set the posts and leveled the entire thing. We used Sika fence post mix which sets up really fast once mixed.

Step 5: Add Numbers

We decided to add vinyl numbers in a modern font to the box. Steph used an outdoor vinyl and cut the numbers on a Cricut Maker. It's been almost a year since we built it and the vinyl has held up really well.

We added a bit of landscaping around the bottom using a piece of leftover no dig garden edging, a bit of mulch leftover from a neighbor's project, and a couple of plants we dug up out of Steph's yard. We are not gardeners at all, but those plants have done so well!

This was a fairly easy build and is a nice improvement over the old box.

Check out the full post on our website.