If your walls are covered with putty, you will need to prepare the surface before installing the concrete slabs. Here are the steps you should take: 1. Remove the putty:
The best practice is to completely remove the putty to ensure a solid and permanent bond between the concrete slabs and the wall.
Alternative preparation:
If it is not possible to remove the putty, you can prepare the surface by installing plasterboard (GK) or OSB, which will then be glued and anchored to the wall. Only then can the concrete slabs be fixed.
Applying the right primer:
A dedicated primer should be applied to the properly prepared surface and a recommended assembly adhesive should be used.