Block walls can be built fairly quickly because of the size of the individual blocks. Still, the same patience and attention to detail involved in laying bricks are required. Check your work often, and don’t be afraid to back up a step or two to correct your mistakes. Everything You Need: Tools: Trowel, chalk line, level, mason’s string, line blocks, jointing tool. Materials: Mortar mix, 8 × 8″ concrete blocks, stakes, cap blocks, rebar, wire reinforcing strips. 
1 Dry-lay the first course, leaving a 3 ⁄ 8 ” gap between blocks. Draw reference lines on the concrete base to mark the ends of the row, extending the lines well past the edges of the block. Use a chalk line to snap reference lines on each side of the base, 3″ from the blocks. These reference lines will serve as a guide when setting the blocks into mortar. 
2 Dampen the base slightly, then mix mortar and throw and furrow two mortar lines at one end to create a mortar bed for the combination corner block. Dampen porous blocks before setting them into the mortar beds. 
3 Set a combination corner block (page 103) into the mortar bed. Press it into the mortar to create a 3⁄8″-thick bed joint. Hold the block in place and cut away the excess mortar (save excess mortar for the next section of the mortar bed). Check the block with a level to make sure it is level and plumb. Make any necessary adjustments by rapping on the high side with the handle of a trowel. Be careful not to displace too much mortar. 
4 Drive a stake at each end of the project and attach one end of a mason’s string to each stake. Thread a line level onto the string and adjust the string until it is level and flush with the top of the corner block. Throw a mortar bed and set a corner block at the other end. Adjust the block so it is plumb and level, making sure it is aligned with the mason’s string. 
5 Throw a mortar bed for the second block at one end of the project: butter one end of a standard block and set it next to the corner block, pressing the two blocks together so the joint between them is 3⁄8″ thick. Tap the block with the handle of a trowel to set it, and adjust the block until it is even with the mason’s string. Be careful to maintain the 3⁄8″ joint. 
6 Install all but the last block in the first course, working from the ends toward the middle. Align the blocks with the mason’s string. Clean excess mortar from the base before it hardens. 
7 Butter the flanges on both ends of a standard block for use as the closure block in the course. Slide the closure block into the gap between blocks, keeping the mortar joints an even thickness on each side. Align the block with the mason’s string. 
8 Apply a 1″-thick mortar bed for the half block at one end of the wall, then begin the second course with a half block. 
9 Set the half block into the mortar bed with the smooth surfaces facing out. Use the level to make sure the half block is plumb with the first corner block, then check to make sure it is level. Adjust as needed. Install a half block at the other end. 
VARIATION: If your wall has a corner, begin the second course with a full-sized end block that spans the vertical joint formed where the two walls meet. This layout creates and maintains a running bond for the wall. 
10 Attach a mason’s string for reference, securing it either with line blocks or a nail. If you do not have line blocks, insert a nail into the wet mortar at each end of the wall, then wind the mason’s string around and up to the top corner of the second course, as shown above. Connect both ends and draw the mason’s string taut. Throw a mortar bed for the next block, then fill out the second course, using the mason’s string as a reference line. 
11 Every half-hour, tool the fresh mortar joints with a jointing tool and remove any excess mortar. Tool the horizontal joints first, then the vertical joints. Cut off excess mortar, using a trowel blade. When the mortar has set, but is not too hard, brush any excess mortar from the block faces. Continue building the wall until it is complete. 
OPTION: When building stack bond walls with vertical joints that are in alignment, use wire reinforcing strips in the mortar beds every third course (or as required by local codes) to increase the strength of the wall. The wire should be completely embedded in the mortar. See page 110 for other block wall reinforcing options. 
12 Install a wall cap on top of the wall to cover the empty spaces and create a finished appearance. Set the cap pieces into mortar beds, then butter an end with mortar. Level the cap, then tool to match the joints in the rest of the wall.
