Backing paper help needed

[bernard35]

Hi all.



I’ve recently stripped wallpaper down to the backing paper. There was a bulge in the wall where the plaster had crumbled behind.



I’ve slit open a pocket and vacuumed out all the loose debris.



I’m planning on keeping the backing paper throughout the room, filling/sanding any bumps or holes.



How can I attach the backing back to the concrete wall and smooth things out to leave a smooth finish?

I’ve attached some photos.
Many thanks

 

[Wayners]

Your going to have to get that section off. Fill and make good wall.
Hang new lining paper over that area.
Probably easier to do the entire wall Vs patch