S-and-Drive Square Duct · End boot connection
Connect boot with S-and-drive
Rectangular boot
Task typeEnd boot connection
Tools / equipmentBoot support, S-lock, drives
Before you start
- Confirm the duct size, end construction, pressure class, seal class, and joint shown on the approved shop drawing.
- Inspect both duct ends for crushed corners, torn locks, bowed panels, loose reinforcement, or shop damage before lifting them into place.
- Make sure the supports are already installed or the sections are otherwise held so the joint is not carrying the weight of the run.
- Stage the correct S-cleats, drive cleats, sealant, hand tools, clamps, and access equipment before starting the joint.
Lay it out
- Confirm the finished ceiling or wall plane and the exact register/diffuser opening location.
- Verify boot orientation, throat direction, collar location, and face size.
- Check for framing or backing needed to keep the boot square at the finished surface.
Set and support it
- Set the boot at the final elevation and secure it independently to framing or structure.
- Hold the face opening square and flush to the finish plane.
- Bring the branch duct to the boot without pulling the boot sideways.
Make the connection
- 1
Fit the S-cleats to the boot connection and branch duct.
- 2
Align the branch with the boot throat so there is no step or twist.
- 3
Start and seat the drives while the boot is clamped or supported.
- 4
Finish the drive ends and seal the connection.
- 5
Recheck the boot face after the branch is released.
- 6
Confirm the register or diffuser can be installed and removed.
Check the install
- The boot face is square, level, and at the correct finish depth.
- The branch is aligned with the throat and does not distort the boot.
- The boot has its own support; ceiling grid or drywall is not carrying duct weight.
- The joint is sealed and the device mounting surface remains usable.
Common mistakes
- Connecting the branch before the boot is secured.
- Using the branch to pull the boot to the ceiling opening.
- Leaving the boot too deep or proud of the finished surface.
- Crushing the throat while tightening a clamp.
Stop and ask
Stop if the ceiling layout is not final, framing/backing is missing, the boot orientation is wrong, or the branch cannot reach without distorting the boot.