Introduction: Modern Mailbox
I took out an old, failing mailbox and built a new, modern mailbox from cedar from the big box store. I'm so happy with it!
I built a small concrete slab to support the mailbox posts, which makes the structure sturdier and keeps the posts from sitting in the ground and prone to rot. But you can also just skip this step if you prefer and extend the posts to put them right in the ground.
Be sure to watch the video above for an even better tutorial.
For the Concrete Form:
- Level: https://amzn.to/31KNLOk
- Concrete Float: https://amzn.to/3sNfo4Y
- Concrete Edger: https://amzn.to/2Opthri
- Galvanized Standoff Post Anchors: https://thd.co/3sPfWHG
- Plastic Mixing Tub: https://thd.co/3mHVMgp
For the Mailbox:
- Circular Saw: https://amzn.to/2WSrF7Q
- Miter Saw: https://amzn.to/2pxpyeu
- Post Level: https://amzn.to/3cPgpnq
- Clamps: https://amzn.to/3cNtI8b
- Pocket Hole Jig: https://amzn.to/2QzkoZh
- Jigsaw: https://amzn.to/2G8twP4
- Drill: https://amzn.to/2ULFuYm
- Sander: https://amzn.to/2uWHM8A
- Mailbox: https://thd.co/3fztKlQ
- Right Angle Drill: https://amzn.to/3ujNUUT
- Wood Finish: https://bit.ly/3ugKuT1
Step 1: Dig and Prepare a Hole
I’m going to make a concrete pad for the mailbox measuring 15" x 25".
I started by digging a hole, bigger than the dimensions above so I had room for the concrete form. I prepared the hole by lining the bottom with gravel, spreading it evenly and level. And then I cut a 2x4 into 4 pieces and screwed them together to make the concrete form with inner dimensions of 15" x 25".
I moved the gravel around until the form was level and the top was even with the ground. And then I took wooden stakes and hammered them in around the form to secure it into place.
You want to make sure the top of your stakes are below the top edge of the form. This way they dont interfere with the screeding process once the concrete is poured.
Step 2: Pour the Concrete
I mixed up one bag of Quickrete in a plastic mixing tub.
Before adding the concrete in, I hosed down the dirt hole. This moisture will help slow down the curing process and avoid cracks. Then I added the first half in, making sure to fill in all the edges and corners.
At this step, I laid in a couple of short rebar pieces. This will add strength and help the slab resist cracking. This small slab could probably get away without them, especially in my warm climate. But the rebar was inexpensive and easy precaution.
I then mixed up more concrete to fill up the rest of the form. I used a scrap 2x4 to screed across the top of the concrete and push it level and into place, making sure to get the concrete to fill all four corners.
I then switched to a concrete float and starting smoothing out the surface. The goal here is to force larger aggregate below the surface, fill in the low spots and create a flat, smooth surface.
Step 3: Add the Post Anchors
I’m setting galvanized post anchors in the wet concrete to hold the posts for the mailbox.
I pressed the anchors down into the concrete, at my measured placement, while it was still very wet and malleable. It’s super important here to make sure they are perfectly level and in line with each other. It’s also important to place them with metal sides facing front and back (this will make sense later).
After most of the surface water had disappeared, I then used an Edging Tool and smoothed and rounded the edges of the slab. And then I left it all to cure.
After a few days of cure time, I pulled away the form from the slab. And then I filled back in the edges with dirt.
Step 4: Set the Mailbox Posts
The inside base of this mailbox is made with pressure treated lumber. I took a 4x4 and a 2x4 and cut them to size on my miter saw.
I set the longer post in the back and perfectly plumbed with it shims, confirmed by a post level. I then clamped it into place and marked where the holes for the bolts will go. And then repeated the steps for the shorter front post.
I drilled out the holes for the bolts. And then put the posts back in place and knocked in the bolts, which are galvanized for exterior use, secured them with galvanized washers and nuts.
And here you can see why it’s important to set the post anchor sides facing front and back. This way the bolts don’t interfere with the wood slats.
Step 5: Add Post Support & Front 2x4
One piece of 2x4 will connect the two posts and create the horizontal surface for the mailbox to sit. I added pocket holes on one side. Then secured it into place with exterior screws on the opposite side. Make sure this support is level.
The last structure board to add is this front 2x4, which will give a little more meat to the base. I clamped it into place, pre-drilled with a counter sink bit and secured it with screws. The counter sink bit will allow the screws to sit below the surface and not interfere with the slats.
Step 6: Add the Slats!
The slats I’m using for this mailbox are cedar, which look good and are a naturally rot resistant wood, excellent for outdoor use. Even better, they're inexpensive fence pickets.
I quickly sanded their rough surface down with my palm sander and cut my first slats to size on my miter saw.
I then made sure this first board was level and then clamped it in place. I used a framing square to line out my screw holes. Then I pre-drilled and screws the slat into place. I’m using exterior trim head screws, which have a smaller head and minimize the appearance.
I kept this process going all the way down (on both sides). I wanted a 1/8th inch gap between each slat, and I found that a steel carpenter square was the perfect spacer.
Taking the time to make sure you screws are in line all the way down will really make a difference in the finished look.
Step 7: Add the Trim Pieces
I cut and installed the front, back and top trim boards with the same screws.
I used exterior glue on this top cap. I could have screwed it on, but no screw holes on a horizontal piece means less ways for water to get in and eventually warp the wood.
Step 8: Add Wood Finish
I love the way cedar looks and I wanted a finish that would preserve the natural cedar color and prevent it from turning gray over time. I’m using Total Boat’s Halcyon Clear Varnish, which is an excellent choice for exterior projects. It is a durable finish that is super easy to apply. It provides excellent UV protection from the sun. It dries fast so you can apply another coat in an hour without sanding. And it dries to a clear satin finish that accentuates the wood grain and improves clarity.
Step 9: Attach the Mailbox
And finally, to attach the mailbox, I grabbed my slim right angle drill and screwed the box to the base.
And with that, this modern mailbox was done!
Step 10: Enjoy!
I'm so happy with how this mailbox turned out! Our curb appeal really improved with this one project and it looks like a pro build. It is not a difficult project and will last much longer than the previous one.
Don't forget to watch the full build video above to see a more detailed tutorial.
Thanks for following along!