The wall should be freed from old wallpaper already to concrete. It happens that the walls are not even. In this case, the putty will not help fix the situation. Here you are most likely to resort to the help of drywall. If you do not know how to remove the paint from the walls correctly, then this is not a problem. You will find all the answers on the Internet. Having studied the article with a detailed description of the preparation of the surface for painting, you will feel more confident when repairing.
Pierce the wall with antibacterial primer before applying a putty.
You can also use a unigirent, which is able to give excellent “adhesion” of the wall with putty. As for antibacterial soil, it allows you to prevent the occurrence of fungi and mold. You can apply soil with a sponge, brush or roller. It depends on what will be more convenient for you. After that, you must wait one day.
Apply a layer of putty on a dried surface. If there are scratches or holes in the wall, you must first plunge them with a small spatula. When the putty has time to dry, you should clean all the putty space with sandpaper. The solution is left only in scratches and recesses. If this is neglected, then subsequently putty will settle in pits and your wall will turn out ugly. Then it will be difficult for you to fix errors. After working with irregularities, you can start applying the main putty. Perhaps you will want to apply several types of putty during repair.