How to Move Duct Away from Wall 

I'm remodeling my house and in the bedroom I'm working on now there were recessed wall registers. They didn't sit flush with the drywall they sat back into the drywall. I removed the registers and I'm patching the hole with drywall, when I noticed that the air duct needs to be moved away from the wall in about an inch or two. In the basement the ceiling covers the duct work going into that bedroom.

I cut it back about an inch and a half with the saw-zall so it fits now I just need to be able to move the actual duct forward.

The one register that was there was a baseboard register but 8ft long. I really want to eliminate the whole baseboard register and put a flat 12x2 floor register.

I only have to move it in an inch and a half and actually a bit less because I wedged a piece of wood behind it and pried it away from the wall a little bit. Taking up the floor would be a pita because the previous owner screwed down every single floor board with multiple screws through the whole house so I'm installing flooring over top.

I could pull that last floorboard and trim enough subfloor to adjust the duct.

So, I'm putting a new floor over the old one and I would cut enough space to work comfortably and replace whatever I took out with fresh materials of the same combined thickness. Just don't cut through the joists. 

I went through the floor and there was a spot in the basement where I could actually slide the ducting all the way back. I cut about 3 inches off and attached it with some self tapping screws and then wrapped it with foil tape.

Both are done. Now to fill what I took away.

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