How to Build a Centered Brick Wall

Lay out the brick wall line with stakes and mason's twine and prepare a concrete footing. Dig a trench with a shovel twice as wide as the wall, usually about 16 inches, and at least one-third the planned wall height, or below the line where the ground freezes. Check building codes for specific requirements on a wall over 3 feet high.

Spread a base of gravel, compact it with a hand tamper and insert steel reinforcing bars in the base at each end and every 4 feet of wall length in between. Place bars in the center of the trench. Fill the trench with concrete and smooth it with a mason's trowel, keeping the rebar vertical and centered. Stretch a straight string line on each side of the base to mark the edge of the bricks for the wall, 12 inches apart.

Mix mortar in a wheelbarrow or large container and begin laying bricks, using a mason's trowel to spread mortar on the base to secure the bottom of the brick and on the ends between bricks. Stand one brick upright at the end as a spacer to keep wall sides 4 inches apart. Lay one row of bricks on each side of the wall for its full length. Use a level to keep the tops the same height and follow the string line to keep the course straight. Set another upright brick at the other end as a spacer.

Start the second course of bricks on each side with a half-brick. Cut a brick in half lengthwise with a masonry saw. Lay the second course to the end; it should stop with another half-brick. Finish the wall, alternating starting end bricks between full and half so that each brick on each side of the wall rests on top of two bricks in a running bond pattern.

Mortar upright bricks in place between the two sides once the desired height is reached, to make a solid end. Fill the center between the wall sides with cement grout to secure the two sides and the vertical rebar. Tamp the grout firmly in place with a board. Fill the cavity to the top of the wall sides and smooth it with a trowel.

Finish the top of the wall with bricks laid in an "L" pattern, with a brick laid lengthwise on one side and two bricks across the width to connect. Alternate the pattern, so the next row has the lengthwise brick on the other side of the wall. Use 12-inch-wide flat stones as an alternate cap, mortared to the bricks.