I'm starting a riding arena next week, big girder trusses every 10 or 12', but like the one I did before for the same crew, I'll have to sit there for a good hour after setting one, while they put all the purlins in. I'd suggest just putting every other one in to still brace it adequately but get me outa there sooner, but at times like that I have to remind myself that I'm not the carpenter running the job, and to just keep my mouth shut and do what they tell me. Counting the money made helps make up for the old carpenter frustration. Like when I see some crews putting every single Teco nail in a joist hanger, while I watch, while the other truss end is nailed solid to the plate, I guess they think the truss may jump up in the air or something, if so, one nail would be good, put the rest in when I'm done, would save them money. Any reasoning given for that 16" layout?