The cut outs separating the shingle tabs line up every other course.
Roofing using half tab method.
It s better to use the factory edges of a half sheet of plywood as a guide.
Check them with a framing square or measure so the lines are parallel with the rake ends.
For example if you re roofing from left to right align the first shingle of the second course so the right side of the shingle.
The simplest way to do this is to use the half tab offset method.
This 1 2 tab has to be cut off where it hangs off the left edge of the gable roof.
Mark the center of each section and use a compass to mark 30 degree angles along the sides of each.
For a racking or midroof pyramid layout method snap two vertical lines called bond lines near the center of the roof the appropriate distance apart.
Three tab shingles are most typically installed with a half tab offset that yields the characteristic brickwork appearance.