S-and-Drive Square Duct · Tight-wall side
Plan an accessible S-and-drive joint
One side inaccessible
Task typeTight-wall side
Tools / equipmentLift, mirror/camera, preinstalled drive
Before you start
- Identify the inaccessible side before the section is lifted.
- Confirm the planned preinstalled drive or assembly method is permitted.
- Arrange inspection by mirror, camera, or open-side access.
Lay it out
- Shift the joint away from the wall if piece lengths can be changed.
- Allow clearance for the hidden drive, S-cleat engagement, sealant, and future inspection.
- Mark the hidden side and installation sequence on the piece.
Set and support it
- Preinstall only the hardware needed for the approved assembly sequence.
- Support the section so it can move into position without scraping the wall or dislodging the hidden cleat.
Make the connection
- 1
Fit or start the inaccessible-side drive as planned.
- 2
Install the top and bottom S-cleats.
- 3
Move the assembly into its final position while watching the hidden lock.
- 4
Engage and complete the accessible-side drive.
- 5
Secure both ends and seal all required areas.
- 6
Inspect the hidden side with a mirror/camera before concealment.
Check the install
- The hidden drive is fully engaged and secured.
- The joint is not trapped against the wall with an open gap.
- Required sealant is continuous on all sides.
- Inspection evidence confirms the inaccessible side.
Common mistakes
- Assuming a hidden drive stayed engaged while sliding the duct.
- Putting the joint directly against a wall with no installation clearance.
- Using sealant from the visible side to cover an unseen gap.
- Skipping documentation because the side cannot be seen normally.
Stop and ask
Stop if the hidden side cannot be installed and verified, the joint can be relocated, or the method would leave an unserviceable or unsealed connection.