How to Do Sumerian Arches

Build up the two supporting pillars on either side of your arch installation site. These should be be made of the same large rectangular bricks as you plan to make the arch section with. Build the supports to the height of the tallest person who will pass through the archway often.

Place a large rectangular brick on top of either support, overhanging the gap between them by 40 percent. Sixty percent of the length of the stone should be placed onto each support to bear the majority of the weight of each stone. Corbel arches, such as the one you are building here, incorporate horizontally stacked bricks, as opposed to radiating stones around the circumference of the arch.

Stack a second layer of bricks over the first applied in Step 2. The Sumerians did not find the use of mortar essential, as their bricks were made with sides flat enough to be dry-fitted into place. Stagger the second layer over the first with the ends of the bricks lining up with the center marks of the previous row of bricks. This layer of bricks will hold the first in place by applying gravitational weight upon them, keeping the overhanging bricks from falling between the supports.

Add subsequent layers of bricks until the gap has been spanned. For most doorways, this should be accomplished in three to four layers of brick, depending on the length of the bricks used. Additional layers of brick can be applied over top of the arch to give strength to the wall assembly, or to add height to the wall.