Focus on the actual issue: equipment connection installed before curb/unit verified.
Photograph or mark the condition if someone else needs to approve it.
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In Equipment Connections: RTU, AHU, VAV, Fans & Louvers, I’m looking at: What do I do when equipment connection installed before curb/unit verified? What should I verify before I cut, drill, seal, cover, move, or install?
Do not
Do not assume the curb is right just because it is installed, and do not field-adapt the opening without approval.