How To Build a Brick Arch
Brick arches can be used to provide structural support but, nowadays, they’re more commonly incorporated into masonry as a decorative feature. Before you can begin building, you’ll need to decide what type of brick arch you want to create.
Horseshoe arches, pointed arches, and Jack arches are popular but segmented arches are most frequently seen on residential land. You may want to install a segmental arch across a gateway or to provide an entryway to patio, for example.
Constructing a Wooden Support
Many people are surprised to learn that brick arches are typically constructed using a wooden support, but you’ll need to have this in place to ensure the arch remains stable while the mortar sets. You can make one of these yourself, by measuring the opening at the highest point (springing line) and cutting plywood to match. Then, you find the exact centre, known as the striking point, and mark it at the bottom of the wood.
You’ll need to tie some string to a pencil, hold the string at the striking point and move the pencil from one end of the springing line to another to draw a semi-circle on the wood. This maps out the arch, while adding two straight lines from the striking point to the ends of the springing line and pinpointing the centre tells you where your keystone will be.
However, if you don’t want to build your own wooden support, there are adjustable pre-made supports available to buy at builder’s merchants or DIY stores.
Building a Brick Arch
Once your support is ready to use, fit it into place, using lintels to ensure it reaches the appropriate height. Frame the opening with wooden lintels, so that it has enough support to hold the arch in place.
Mix the mortar and add it to the top of each brick pillar at the sides of the arch. Then, add one brick to each side, ensuring that the centre of the brick lines up with the striking point. Continuing adding bricks one at a time, alternating each side until you add the keystone brick. When you place the keystone brick, it will lock the rest of the bricks into place and transfer the tension from the wooden frame to the pillars.
It may take a few days for the mortar to set completely, but, when it has, you can remove the wooden support and admire your new brick arch!