Traditional Hangers & Supports ยท Supports & Hangers

Insulated duct on trapeze with shield

Exterior insulation

ConnectionSupport method only
SupportTrapeze plus insulation shield

Before you start

  • Confirm the approved support detail, actual duct weight, support spacing, attachment substrate, hardware size, corrosion protection, and any insulation, seismic, vibration, or rooftop requirements before installation.
  • Confirm the insulated outside dimension, insulation type, vapor-barrier requirement, shield or saddle size, support spacing, and exterior jacket condition.
  • Inspect insulation and jacket for tears, wet areas, crushed spots, and missing vapor seal.
  • Verify the shield spreads load without creating a thermal or condensation bridge.

Tools and materials

Approved trapeze, insulation shield or saddle, high-density insert where specified, vapor-barrier repair materials, jacket repair materials, level, tape, lift, clean gloves, and retainers where required.

Lay it out

  1. Lay out support points clear of joints and fittings.
  2. Size the trapeze to the insulated outside dimension.
  3. Keep shield edges away from jacket seams where possible.

Set and support it

  1. Install and level the trapeze.
  2. Place the approved shield or saddle.
  3. Install a high-density insert only where the insulation system detail requires it.

Make the connection

  1. 1

    Inspect the insulation and vapor barrier at the support point.

  2. 2

    Raise the duct and land it evenly on the shield.

  3. 3

    Center the load over the trapeze.

  4. 4

    Install retainers without puncturing or crushing the jacket.

  5. 5

    Seal any approved penetrations or repairs.

  6. 6

    Release the lift and inspect for compression.

  7. 7

    Recheck the vapor barrier after final adjustment.

Check the install

  • Insulation is not crushed.
  • The vapor barrier and exterior jacket remain continuous.
  • The shield spreads load evenly.
  • No condensation bridge or exposed metal path is created.
  • The duct remains centered and level.

Common mistakes

  • Supporting insulated duct directly on narrow strut.
  • Cutting the vapor jacket and leaving it open.
  • Using a shield too short for the load.
  • Overtightening retainers through the insulation.

Stop and ask

Stop if the support crushes insulation, tears the jacket, breaks the vapor barrier, or creates an unresolved condensation bridge.