I think mine are 14 gauge as well.
But like others have stated, the design is the key. (i.e. roof pitch, truss's, local snow load requirements...etc)
One thing I'll mention, just because I was recently talking to a buddy about it, is to be careful of how you insulate it, if you do.
My buddy was telling me of a guy that "spray foamed" his metal building and it buckled the hell out of the skin of the building when it set up.
He says it looks like the building belongs in a Dr. Seuss book now.
I can't remember the details, cause I was laughing so hard, rum and seltzer were shooting out of my nose...
Apparently, he should have lined the the walls with some sort of Tyvek or something to prevent the insulation from sticking to the metal skin.