Duct gauge or reinforcement changes mid-run and I do not understand why
Treat duct gauge, reinforcement, pressure class, and joint type as shop/spec-controlled items. Do not guess or substitute because a piece looks lighter or heavier.
Do not decide gauge, reinforcement, or pressure-class construction from memory. Do not remove reinforcement because it is in the way.
Check
Check the shop drawing tag and duct construction notes.
Compare pressure class, size, gauge, joint system, reinforcement, and support detail.
Photograph the piece and the drawing callout.
Ask before changing gauge, reinforcement, tie rods, joint system, or support spacing.
Steps
Check the shop drawing tag and duct construction notes.
Compare pressure class, size, gauge, joint system, reinforcement, and support detail.
Photograph the piece and the drawing callout.
Ask before changing gauge, reinforcement, tie rods, joint system, or support spacing.
Say this to your foreman
This run changes from [gauge/detail] to [gauge/detail] at [location]. Can you verify the pressure class/reinforcement requirement before we install it?