In commercial we always stand the boards up, especially on rated walls, that way we don't have flying edges.Do any pro drywall contractors prefer to install board vertically on the walls? I haven't seen it done that way much for reasons I thought I knew. I assumed it was because of electrical outlets and switches, header joints at windows and doors etc. Is there other reasons? It would eliminate butt joints. The reason I asked is my neighbor diy guy is building a house and I offered to sell him 6 sheets left over 1/2" 12' rock to get it out of my way. He said he can't use it because he's using all 8' rock on the wall so he can run it vertically and not have any butt joints.
In residential we have always ran the boards horizontal in most cases, not sure why we do it that way, we just always have, I think because it is easier to hang, because one guy can put the bottom board up by himself with a board lifter and then stack the top board on top of it by himself, and by staggering the joints, it is easier to hide the butt joints.
If the guy needs 8' boards, he could just cut the 12' boards down.