While bricks have a 6:5 height-to-width ratio, beams
maintain a 7:8 ratio. A simple beam can be up to 15 studs
long, but it is always 1 stud (8 mm) wide and 7 mm tall. For
example, notice the slight height difference between the
9.6 mm tall brick and the 7 mm tall beam in Figure 2-14.