I cannot drive the back S-cleat on a blind duct drop
If the back S-cleat cannot be reached, do not leave the joint loose and hope sealant saves it. Pull back, verify access, and use an approved blind-joint method that can be mechanically fastened and sealed.
The back side of this vertical drop is blind and I cannot drive or seal the rear S-cleat from the front. I checked inside access and whether we can pull it back. Do you want an internal collar/slip, standing S/front-access method, or a preassembled drop detail?
Watch out
Do not leave the back S-cleat loose, smear what you can reach, and bury the drop in the wall or chase.
Check
Confirm which side of the joint is blind and whether you can safely reach it from inside, above, below, or before lowering the next piece.
Check whether the duct can be pulled back enough to preassemble or change the connector.
Verify the joint will have mechanical engagement, sealant access, and inspection/repair access before you bury it in the chase.
Look for sharp edges, fall/drop hazards, and whether another trade or wall closure will block the fix.
Take a photo and mark the location before asking for the connection decision.
Steps
Confirm which side of the joint is blind and whether you can safely reach it from inside, above, below, or before lowering the next piece.
Check whether the duct can be pulled back enough to preassemble or change the connector.
Verify the joint will have mechanical engagement, sealant access, and inspection/repair access before you bury it in the chase.
Look for sharp edges, fall/drop hazards, and whether another trade or wall closure will block the fix.
Take a photo and mark the location before asking for the connection decision.
Say this to your foreman
The back side of this vertical drop is blind and I cannot drive or seal the rear S-cleat from the front. I checked inside access and whether we can pull it back. Do you want an internal collar/slip, standing S/front-access method, or a preassembled drop detail?