Flooring – Example Registers for 2“ x 12” Duct

Filling the holes is the easy part. You put a scrap of 2x4 under the floor across the hole on each side and run screws through the existing subfloor to fix the scrap in place. Then just fit a piece of sub floor in the opening and screw it onto the 2x4's.

The hard part is replacing the flooring itself. If it's hardwood, you have to try to match the grain and probably remove a few pieces so there isn't an odd rectangle in the grain. If it's carpet, you need to get a scrap of carpet (hopefully one was left from the last install), align the grain of the patch with the existing carpet, and fix the scrap of carpet in place with glue strips that are heated with a special iron to melt the glue. A professional carpet installer can make this spot disappear in a way most DIYers can't.

Since you have a temporary solution in place with the vents that are there, I'd suggest holding off on removing them until you decide to replace the flooring if that's at all convenient.

In case someone comes across this in a future search, here is what I did on a similar project:

First, I used an oscillating saw with a plunge bit to cut the nails—-much easier than a sawzall. I used little magnets to sweep along the face of the stucco mould and locate them, then I plunged in from the side to cut them. I cut the paint with a utility blade along the seam where it joined the frame and tapped the mounding free with a hammer & chisel (aka screwdriver).

Then I cut the door frame nails with the plunge bit from the front and back after locating them the same way. Since my door also had zero gap between the frame and the studs, I had to do some persuading with a hammer to move the stud where I wanted it, plus a slight trimming of the bottom plate with a hand saw. My header was also nailed out of level and I had to tune up the corner with an actual chisel.

Now, my stucco molding was 1” thick and they apparently do not make that any more, so it was impossible to replace (would have been easier to paint and reuse it but it was in rough shape). I had to go with the 3/4” stuff. I also went with a door frame that was ~1/4” wider to compensate (old was 4-1/4”, new was 4-9/16”). The shape of the channel turned out to be different as well, so I simply cut off the exposed lip of the stucco with an angle grinder with a diamond wheel. I also had to rip off the lip of the stucco moulding on my table saw.

I had to cut the top of the stucco about an inch higher to match the new, standard sized door frame I bought from the big box store. I used a grout blade for my oscillating saw to do the corners. To finish I used OSI Quad caulking between the stucco mounding and stucco and it turned out great, no need to repaint anything because I cut a nice clean edge.

As you can tell, I ran into every single nightmare possible! But I could see all of them coming, had the right plan and more importantly the right tools. I wanted to share my experience in case someone else is looking to do the same job. Good luck!