I've framed the pool house and before I put the rafters up, I have to stabilize the building. Stud frame construction is flimsy until the walls, footers and headers are all nailed together. I have seen folks construct buildings only to have them fall when the rafters were put on. Having your building collapse is inconvenient and potentially dangerous. At any rate, when it collapses, you have to start over.
Talking with Daddy last Sunday after church, he cautioned me to sheath the building before putting the roof on. I'm sure I would have remembered, but it never hurts to be reminded. Riding a bunch of rafters to the ground would probably have tempted me to cuss. There is cussing enough in carpentry without doing something stupid.
So, I am sheathing the building with 1/2 inch CDX sheathing. It's plywood, for you non-carpenters. Sheathing the building gives it stability as the plywood is nailed to studs, headers and footers. Plywood makes the building rigid and adds support to the walls. It's going to take nine sheets, and I have five installed. With temps in the upper nineties, I'm taking my time.
Yet, if I swing a hammer for a couple of hours every day, this thing will eventually be completed.