Flat-oval exposed run

Before you start

• Confirm the flat-oval size, major and minor axis orientation, material, pressure class, joint type, and support detail against the approved drawing.
• Inspect the duct for sidewall dents, flattened ends, twisted axes, damaged beads, split seams, and shipping damage before lifting it.
• Check that the mating pieces use the same oval profile. A round-looking end and a truly matched flat-oval end are not the same thing.
• Stage the correct fittings, joint hardware, approved fasteners, sealant or gasket system, supports, lifting equipment, and hand tools before starting.
• Review the architectural finish, seam orientation, joint spacing, hanger appearance, label removal, and approved touch-up method before material is lifted.

Lay it out

1. Laser the visible centerline and bottom elevation through the entire exposed run.
2. Lay out joints, hangers, seams, and fittings in a consistent visual rhythm where field conditions allow.
3. Mark the preferred seam orientation and visible face before the section leaves the ground.

Set and support it

1. Install and level the exposed supports before lifting duct.
2. Use padded contact surfaces and soft slings to protect the finish.
3. Keep the duct controlled at more than one point so it does not swing into structure or other installed work.

Make the connection

1. 1

   Inspect and clean the mating ends before the pieces are raised.

2. 2

   Set the first section on the finished support and align its visible face.

3. 3

   Bring the next section into line without dragging it across the support.

4. 4

   Complete the approved connection while protecting the visible surface from tools and metal shavings.

5. 5

   Finish fastener and seam orientation consistently with adjacent sections.

6. 6

   Apply only the required sealant and clean any smear immediately using the approved method.

7. 7

   Remove labels, fingerprints, and layout marks after the run is stable.