Redo inner wall plywood/gypsum

[Svedlund]

Hello all construction experts!
I'm renovating a few rooms and considering whether I should take the opportunity to install new wall panels since I'm planning to wallpaper anyway. I want to have plyfa under gypsum... to stabilize and avoid having to plug every time a shelf needs to go up... but I don't want to tear down entire walls, just take a few rooms at a time.
Currently, I have single-layer gypsum.
But... the interior walls have metal studs, and if I start tearing down the old gypsum boards, the metal studs will likely get damaged?!? And that means I'll have to tear down the entire wall and restud, ending up having to redo 4 rooms instead of the two I originally intended...
Or should I just put plywood on the existing gypsum boards and then another layer of gypsum on top of that?
Grateful for a smooth, cost-effective answer

 

[tgr_se]

Look for the screws with a magnet. It should work despite metal studs. Then use a morakniv to cut out a bit so you can expose the screw. Then you just unscrew the board. It goes quite quickly once you start to see the distance at which they placed the screws.

 

[Svedlund]

Look for the screws with a magnet. It should work despite the metal studs. Then use a Morakniv to cut out a bit so you can get to the screw. Then just unscrew the board. It goes pretty quickly once you start seeing what distance they placed the screws at.

Tested with a magnet and it seems to work... but what a time it will take
But well... if you want it the way you want, maybe that's what you have to do

 

[Svedlund]

First found! Thanks for the tip... it will be a whole day to look for screws!
The first one was very conveniently placed... poor monkey! (The kids' room)

 

[JLyck]

I did that when I took down the drywall in our old kitchen. It actually didn't take that long. After a few screws, you start to get a sense of how far apart the screws are.