How to Build a Letterbox out of Plywood or Bricks

Learning how to build a letterbox allows you to choose the perfect design and materials to ensure your mailbox lasts year after year and is designed to suit your style and complement your home. If you’re tired of your leaky, rusty mailbox, or your mailbox is currently falling apart, then this guide on how to build your own out of wood or brick can walk you through the building process so you end up with a letterbox you’ll love, one that you’ll be proud of, and a model that will last for years to come.

Wood Letterbox

Fortunately, building a new letterbox out of wood is simple and easy. Follow the steps below and you’ll end up with a beautifully finished wood mailbox that will be a true asset to your home.

The First Step

While this is a very simple project, you’ll need to use the following tools to get the job done right:

  • Spade
  • Waterproof glue
  • Marking gauge
  • Measuring tape
  • Carpenter’s square
  • Pencil
  • G clamp
  • Spirit level
  • Nail punch
  • Claw hammer
  • Wood drill bits
  • Circular saw
  • Jigsaw
  • Electric drill
  • Handsaw

Materials Needed

You can make this mailbox using exterior grade plywood, measuring in at 1200 x 900 x 19 millimeters. Plywood is a great option since it offers a better weight to strength ratio compared to solid pine, which is also commonly used for letterboxes. However, plywood will retain its shape and will not warp, regardless of the climate. Yet, just like pine, it should be painted or stained in order to complement your home and to further protect it from water damage. For a support post, I recommend either red gum or you can use a treated pine. The post should measure in at 90 x 90 x 1500 millimeters.

Cutting and Measuring

Before making a cut, make sure that you square it and measure it accurately. Cut one board to 230 x 185 millimeters. Next, you’ll clamp this piece on top of the main board. You will need to saw another piece using the same measurements. Make sure you use some scrap wood under the clamp’s jaw in order to prevent leaving any marks behind when you cut.

The next part you’ll cut is for the roof. Measure the angle of the roof, marking a line down the center of each of the pieces you’ve just cut. Use a tape measure and measure 118 millimeters up from the bottom, squaring the line across the width. Use your pencil to draw another line from the 118-millimeter mark one for each edge all the way to the top center line. Now you’re ready to cut the roof.

For the door opening, you’ll cut out a piece from the rear of the board, measuring 150 x 118 millimeters. Using your tape measure, draw a line for 118 millimeters from the bottom on each side, squaring the line across it. Next, measure 40 millimeters from each side and down for the proper door opening size.

Use your electric drill and drill a couple of holes using a 10-millimeter drill bit at the top two corners, then you’ll make another cut along the top line, then down the sidelines, with the help of your jigsaw.

vintage mailbox

Mail Slot

For the slot, you’ll measure 118 millimeters from the bottom on each side, squared off. You’ll do it again from the bottom, measuring 98 millimeters and square off. Use a spade drill bit at 25 millimeters and drill a hole in each end, cutting along the lines in order to form a slot. Smooth the edges using some ultra-fine sandpaper.

For the roof, door, bottom, and sides of the letterbox, you’ll need to make a couple of identical sides measuring in at 330 x 175 millimeters. Carefully measure and cut out the marked section for each side.

To make the roof, you’ll need two pieces of wood measuring in at 410 x 175 millimeters. You’ll need to cut a thirty-degree angle with the help of a block plane. This will ensure that the roof will be joined evenly and neatly at the peak. You may need to make some tweaks to the design based on how accurate your cuts were.


  • Begin by assembling both the ends of each side, using the waterproof glue and evenly spreading it along the rebates. Next, nail the sides. This step should be repeated for the bottom piece. Make sure that the edges are flush.
  • Place the roof pieces in the correct position, doing one section at a time. There should be an overhang of approximately 20-millimeters on each side and 30-millimeters back and front. Nail and glue the roof in place. The second section of the roof should now be in position. Check to ensure the fit is perfect before you nail it and glue it in place. The nails should be punched directly below the timber surface.
  • On the opening and the door, cut out a small recess to allow the hinges to fit neatly in place. Screw them in and make sure that the door is able to open and close easily. Align and staple the catch and hasp to lock the door securely in place.


Place the mailbox on top of the post, drilling a 4-millimeter hole through the curved supports and fixing blocks, and secure the mailbox in place using 50-millimeter screws.

Finishing Your Wood Mailbox

For the final touches, make sure you punch all of the nail heads right below the surface of the wood, filling each hole using some wood filler. Next, sand the whole mailbox using sandpaper and be sure you round off any sharp edges. To finish it off, coat the wood using an oil-based paint that’s designed for exterior use. You can also use a pigmented stain to protect the wood.

Making a Brick Mailbox

nice mailbox

If you want a mailbox that’s more durable than wood, then your best option is making one out of bricks. For this style of letterbox, you’ll basically be building a brick enclosure that will surround a standard mailbox of your choosing, whether it’s an existing mailbox or you’ve made the plywood mailbox using the instructions I’ve included above. Brick mailboxes can last for decades and are basically maintenance free, unlike models made out of wood. This project is a little more complicated than the wood letterbox, but again, considering how durable it is, it’s definitely worth the extra steps required.

For this project, you’ll need to purchase the following supplies:

  • Bricks of your choice
  • Premade mortar
  • Brass faceplates
  • A premade letterbox

Following the instructions below, you’ll learn how to cut bricks, mix up a batch of mortar, and lay the bricks surrounding your plywood or pine mailbox, for a new look and a mailbox that’s pretty much indestructible.

How to Cut Bricks

Position bricks on solid ground. Use a bolster, hitting it firmly with a hammer on every side for solid bricks, and only on a single side for any extruded bricks. Using a hammer, you can straighten up the edges.

Next, lay out the base of bricks on a concrete slab, using string lines for the back and front, squaring up the ends using a builder’s square, marking the bricks on the footing. Remove any of the bricks that are ready to be laid, once the mortar has been mixed.


You can mix up some mortar using pre-mixed mortar, which will make this step fast and simple. Mix it up in a wheelbarrow with a shovel until it’s evenly mixed.

Concrete Footing

The first step to making a mailbox out of brick is marking out the footing. You’ll want to allow for 75 millimeters around the brickwork, so you’ll need to remove dirt to 250 millimeters deep. Mix and pour some concrete and use a float in order to ensure a level surface.

Laying the Base

Once the concrete is completely dry, you’ll set string lines for the base course and trowel on a bed of mortar that’s 20-millimeters deep. Lay the initial course and maintain a 10-millimeter mortar joint. Be sure to check that the corners are square. You can do this using a builder’s square.

Building Up the Corners

Get rid of the string lines, building up the corners and begin at the open end. This should be done using brick bond joints that are staggered. Make sure you only work at one end at a time and check that the bricks are straight. The goal is to shoot for five courses across the ends.

Filling the Corners

Place the string line from corner to corner, making sure they’re in line with the top of the next course. On the top of the last course, trowel more mortar, making sure you batter the mortar and bricks into position. Use a spirit level to check your work and complete a total of seven courses.

Add a Faceplate

A faceplate will be a beautiful touch. You can attach a brass faceplate with the help of some stainless-steel screws.

Install a Mailbox

You can purchase a premade mailbox or make the mailbox out of plywood or pine, using the instructions that I included at the beginning of this guide.

Start by positioning the brass slotted front plate using a threaded rod on each side. The rods should be bent to a hook behind the bricks. Seal the edges of the mailbox with silicone, leaving the base. Place mortar on each side, cutting the bricks to fit, then lay the top course over the letterbox.

And that’s it. You now have a durable, beautiful brick covered mailbox that’s designed to last for years.

Final Thoughts

Learning how to build a letterbox is simple and easy and it’s a great project for you and the kids. You can make a mailbox out of wood, stainless steel, aluminum, or brick. The type of design and materials you choose should be based on the type of climate you live in and the style and look of your home. Both of the plans included in this guide were created with the beginner in mind, so even if you’re not very handy in the garage, you should have no trouble creating your own mailbox following these basic steps, the included supplies list, and some power tools.