My old lead drafter told me to always dimension to the center of a beam, not the edge, and I finally saw why on a job last week

3 comments

3 Comments

Yeah, that's one of those rules that seems pointless until you're the guy on site trying to make it work. I learned that lesson the hard way after a few too many confused calls from the field. My old boss would just shake his head and say the centerline doesn't move, even when everything else does. It finally clicked for me after a project where the steel was off by half an inch, but because we dimensioned to center, it all still fit together. Felt like a real "oh, that's why" moment.

grant.anthony1mo ago

Exactly, @reese_perry6, though I'd argue the centerline can move if you're working from a known, fixed point instead.

the_elliot24d ago

Wait, so @grant.anthony are you saying the fixed point becomes the new center? That's where I get hung up. If your known point is a column or a corner, you're still basing everything off that one spot, but then your centerline is just a measured line from it, right? So the centerline itself isn't moving, you're just picking a different starting place to find it. Or are you talking about a situation where the physical center actually shifts?