How to Make an Arched Brick Wall

Build the Arch Template

• 1

  Build a template that will be used for the duration of the project. Measure across the brick wall opening -- and establish the precise midpoint. Place a piece of thin plywood across the opening, then mark the midpoint on the board and tap in a nail. This midpoint becomes the archway’s center mark.

• 2

  Tie a piece of construction string to the center mark’s nail, and stretch the string to one wall. Tie a felt marker to the string and, with the string taught, draw a radius over the face of the plywood. This radius will become the interior arch, or the intrados, of the opening. Mark the center point of the radius.

• 3

  Tack or clamp a second piece of plywood beneath the marked piece and, using a jigsaw, cut the two plywood pieces together to form identical shapes. Cut a 2 by 4 the length of the bottom of the opening to use as a base between the plywood arches. A supplemental support board may be used to stabilize the arch form. Fashion a thin piece of plywood over the arch, and attach it to the exterior edge of the arch.

Building the Arch

• 4

  Support the arch form by nailing two 2 by 4s to the existing brick walls, using masonry nails. Leave a small gap to place a trim piece of wood across the opening atop the support boards. Place the form on top of the cross-support board. Use one shim per corner to level the form precisely.

• 5

  Mix the mortar thoroughly into a semi-firm consistency. Nail two flat boards on the face of the wall -- and run a guide string between them, moving the string upward to accurately level the bricks during construction.

• 6

  Place a thin layer of mortar between each brick, working each side consistently with the other. Shape the mortar wedge into a pie-shape, leaving a half inch on the interior arch and the exterior wedge, consistent with the radius of the arch.

Accuracy and Finishing

• 7

  Use the construction string placed at the center mark throughout the project to accurately lay each brick. Hold the string against the edge of each brick to maintain consistency in designing the arch.

• 8

  Place the center brick, referred to as the "key brick," and add mortar to fill any gaps during construction. Touch up mortar work with evenly consistent grooves.

• 9

  Allow four to seven days, depending on the humidity, for the mortar to completely dry. Deconstruct the form and blocking with care. Remove the shims, allowing the form to shift downward and away from the arch. Remove any boards and nails, and clean up the site.