How to Make a Brick Mail Box on Concrete

Set 1-by-2-inch boards on their edge to form a 16-by-16-inch square that marks the footprint of the mailbox. The square must measure 16 by 16 inches when measured inside the boards.

Place a carpentry level on top of the concrete pad, inside the marked mailbox footprint. If the pad isn't level, mix a quick setting concrete, following package instructions. Smooth the concrete onto the pad with a trowel, smoothing the surface between the 1-by-2-inch boards, to form a level surface for the mailbox construction. Allow the concrete to harden completely before removing the boards.

Apply lines of masonry caulk adhesive around the bottom edges of the 16-by-8-inch cinder blocks. Set the blocks, caulked side down, side-by-side on top the prepared concrete pad to form the base for the mailbox.

Mix masonry mortar with water in a large bucket, following package instructions. Smooth the mortar onto the block base in a 1-inch deep layer.

Place the bricks on top of the mortar, placing them around the inside perimeter of the block base to form a square of bricks with a hole in the center. Smooth a ¾-inch layer of mortar on the side of each brick before placing the brick next to it. Use the edge of the trowel to remove and smooth any mortar that presses out between the joints.

Use the level to check that the first course of bricks are still level, and adjust the mortar thickness as necessary to ensure they are. Continue mortaring and adding new courses of bricks, offsetting the brick joints between each course.

Fill the hole in the interior of the brick square with mortar once the mailbox is five courses tall. Continue adding courses, filling in the center every five courses, until the brick sits 40 inches tall.

Set your mailbox on top of the brick column. Center it and place it far enough forward so that the door opens easily. Attach the mailbox to the brick base with mortar once you are satisfied with its placement.

Finish adding brick courses to the top of the mailbox. Use additional mortar between the mailbox and the bricks to fill the gap between the curved sides of a standard mailbox. Alternatively, use a rectangular mailbox so you don't have to work around the curves.

Smooth mortar over the top of the mailbox to create a level surface. Lay a final brick course over the top of the mailbox to finish it. Fill the holes in the top bricks with mortar and smooth it with the trowel.