Taps & Takeoffs · Taps & Takeoffs
Tap into double-wall duct
Double-wall main
ConnectionDual-wall collar system
SupportIndependent branch support
Before you start
- Confirm double-wall construction, insulation thickness, inner collar system, outer collar system, and branch route.
- Inspect inner liner, insulation, and outer shell.
- Plan the inner-air-barrier inspection before closure.
- Control debris in both wall cavities.
Tools and materials
Dual-wall tap collar system, cutting tools, inner-collar sealant, insulation repair materials, outer-shell components, clamps, fasteners, branch support, and inspection light.
Lay it out
- Mark outer and inner openings.
- Keep the tap clear of double-wall joints and supports.
- Align the branch centerline.
Set and support it
- Support the main.
- Support the branch independently.
- Keep both shells stable during cutting.
Make the connection
- 1
Cut the outer shell.
- 2
Remove insulation locally without damaging surrounding material.
- 3
Cut the inner liner accurately.
- 4
Install and seal the inner collar.
- 5
Inspect the inner air barrier.
- 6
Restore insulation.
- 7
Close and seal the outer collar.
- 8
Connect and support the branch.
Check the install
- The inner air barrier is sealed.
- Insulation is restored.
- The outer shell is neat.
- The branch is independently supported.
Common mistakes
- Closing the outer collar before inspecting the inner joint.
- Leaving an insulation gap.
- Cutting both walls at once.
- Letting debris remain between walls.
Stop and ask
Stop if the inner joint cannot be inspected before closure, insulation cannot be restored, or the dual-wall system is unclear.