The mason is laying the second course of a foundation or stem wall. The red arrow highlights a “line block” that tightly extends from one corner to the other. This masonry technique allows for the mason to place block on the wall using the line as a guide, which greatly speeds up the process without sacrificing accuracy in the wall being level and plumb. The actual line is faintly seen running the entire wall.

The second course is installed and awaits grout. Notice how straight the wall. This was this mason’s first experience not only laying Omni Block, but using a line and a level. He laid 208 block his first day indicating that the learning curve is minimal and he did it without any block cuts. The 39cm block in length and 1cm mortar joints in conjunction with 20cm design increments allowed for this type of success.