I have removed the textured wallpaper from the wall and the concrete is now exposed. There was a significant amount of glue, and I have used warm water with sugar soap and a scraper to remove as much of it as possible (the process was repeated 3-4 times and little glue was removed on the last pass, but the wall still feels very slightly sticky when wet).
Small holes have been patched with setting compound and then sanded. The wall is now fairly smooth, with some irregularities.
I am looking for a smooth (but not necessarily perfect) wall and long-lasting paint job so the glue is a concern. I am thinking about proceeding as follows:
- Apply a layer of sealer to the wall (Zinsser Gardz High Performance Sealer, a water-based product. It looks like oil-based sealers were popular in the past but because of their smell and thanks to technical progress water-based sealers are now a good option.)
- Skim coat the wall with some gypsum-based joint and filler compound, then sand (repeating the process twice).
Does it make sense to process in this order or should skimming happen first? Would this method yield good results?
I'm aware skimming can be tricky but I'm happy to learn how to do it. I have considered putting wallpaper on the wall but would prefer not to if there are decent alternatives.