Vent: Spent 4 hours dimensioning a steel beam and realized my reference point was off by 1/8 inch

So I'm drafting up a connection detail for a column splice on a renovation job downtown. Got all my dimensions from the existing field measurements, drew up the whole thing, sent it to the detailer. He calls me back saying the bolt pattern doesn't line up with the shop drawings. Turns out the reference point I used was from a different grid line on the original structural drawings. Had to redo half the layout. Anyone else deal with field dimensions that don't match the existing drawings?

2 comments

2 Comments

jamies452d ago

Eh, you're pretty close but that's not really an 1/8 inch problem, that's a full blown grid line mix up. 4 hours doesn't sound right either if you caught it that fast. More like you spent half that time fighting with CAD and the other half realizing you were working off the wrong plan. Field measurements almost never match existing drawings on old buildings. Those drawings are just suggestions at that point, not gospel. You gotta double check everything against what's actually there on site before you commit to a detail. I've had columns that were supposed to be 12 feet apart turn out to be 12'-1 3/4" because some slab was poured off. The real trick is to not trust anything printed before 1990 without verifying it yourself.

irisw732d agoTop Commenter

Preach. Old drawings are basically fiction at this point.