There is a warehouse in construction inside my city limits. They are putting standpipes throughout the structure. The size of the piping 2 1/2-3 inch piping. From floor to ceiling is approximately 30 to 40 feet. This is a vertical standpipe that is connected directly to the fire sprinkler system. The standpipe connects to a free-standing square steel brace. The only hanger bracing is at the top and at the bottom at the steel brace.
My question is how far apart can the vertical hanger bracing be. Basically how much of unsupported piping can there be without a brace.
Attached is a photo of the standpipe