Tolerance Stacking Across Trades
A precast or prefab connection has to absorb manufacturing tolerance, erection tolerance, and in-situ foundation tolerance all at the same joint — and each of those tolerances is set by a different trade, on a different schedule, often without visibility into the others. Connection details that assume a single, generous tolerance band instead of stacking the real tolerances from each source are a common source of on-site fit-up problems.
Detailing the Connection, Not Just the Element
Shop drawings that fully detail the precast element but leave the connection as a generic callout push the real engineering decision onto whoever's erecting the piece on site — exactly the wrong point in the process to be resolving load path, bearing, and grout-pad specifics. A connection detail needs the same rigor as the element itself: bearing pad material and thickness, weld or bolt specification, and a stated sequence for grouting or dry-packing.
Sequencing the Erection to Match the Detail
A connection detail that works on paper can still fail if the erection sequence doesn't match the assumptions it was designed around — temporary bracing removed too early, or an adjacent element not yet in place to provide the lateral restraint the connection relies on during the interim condition. The erection sequence and the connection detail need to be reviewed together, not handed off as two separate documents.