Rough-In HVAC
CSI Division 23, HVAC
The mechanical installation performed inside walls, ceilings, and floors before they're closed up, such as ductwork runs, refrigerant piping, and condensate drain lines, installed and pressure-tested while it's still visible, alongside the equivalent rough-in work happening for plumbing and electrical in the same spaces.
Why it matters
HVAC rough-in competes for the exact same ceiling and wall cavity space that plumbing, electrical, and fire sprinkler rough-in also need, so a project that lets one trade rough-in without coordinating with the others can end up with a physical conflict that isn't discovered until someone tries to close up the ceiling.
On a real project
A mechanical contractor completes ductwork and refrigerant line rough-in on a floor, coordinating routing with the electrician and plumber ahead of time using a combined coordination drawing, then has the completed work inspected before drywall and ceiling grid close over it.
Who this matters most to
An HVAC Technician installs rough-in mechanical work to the mechanical drawings, routing around conflicts identified during coordination. A Superintendent sequences HVAC rough-in against electrical and plumbing rough-in in the same space, since all three trades often want the same ceiling cavity at the same time.
Where this goes wrong
A mechanical crew roughs in ductwork through a corridor ceiling without checking a recently issued coordination drawing showing a fire sprinkler main now routed through the same space. The conflict isn't caught until the sprinkler crew arrives and finds no room left to run their line, forcing a rework of ductwork that had already passed its own inspection.