How to Lay a Double-Thick Flemish Bond Brick Wall

Check building codes before starting any brick wall project. Walls for buildings will require permits, as will freestanding walls over 4 feet high and possibly any used as retaining walls. Determine soil types where the wall will be built and frost lines, which is the depth at which the ground freezes. Measure the length and height of the wall with a tape measure and multiply those figures to get the square footage to buy bricks.

Build a solid concrete foundation. Dig a trench with a shovel below the frost line and as wide as half the height of the wall, 18 inches for a 3-foot wall, for instance. Line the bottom with compacted gravel and use dirt as forms for the sides, if it is solid, otherwise build wooden forms to line the foundation. Pour in concrete, push it solidly into the trench with a board and smooth and level the top with a trowel and a level.

Choose a type of Flemish bond, which alternates stretchers and headers in a pattern. Use a basic Flemish, which alternates stretchers and headers in the same course or use some variations. One alternates a full stretcher course with a full header course every other course, while another style uses full headers every third course.

Lay the first course in a half inch of mortar spread with a trowel on the concrete base. Set stakes and a mason's twine line along each side to keep the sides straight. Mix mortar so it spreads easily but does not run or drip. Set the first brick in the mortar, check it with a level, and put the next brick beside it, with 3/8-inch of mortar in the vertical joint. Lay one full wall length, two bricks wide, with either all stretchers or alternating stretchers and headers, depending on the pattern you chose.

Start the second layer of bricks with a header brick across the end, if you chose the alternating stretcher/header pattern, or with half-brick, cut with a mason's saw. Arrange the pattern in the single layer Flemish style so that header bricks are in the center of the full bricks beneath. Lay alternating courses by placing a layer of stretchers and laying a full row of Flemish headers across them from one end of the wall to the other.

Lay bricks to the desired height, checking continuously to ensure courses are level and wall sides are plumb and straight. Finish with a cap layer of all headers, laid flat with the 4-inch side up. Reinforce any wall higher than 3 feet with steel reinforcing bars or strips laid in mortar joints, vertically in between the two outside layers or horizontally across the brick faces.