The underlayment is the water control layer; valleys, crickets, and chimneys are the most vulnerable spots
Roofs peel off from the edges, so it is critical to hold them tight
Left-, right-, and straight-cutting snips with single- and compound-leverage each have their place on a jobsite
A California valley is faster than cutting all of the shingles up a valley. With shingles bedded in cement, it can be exported to other states.
The top reason to study engineering in college: Wall of Wind. Yay Science!