I am in need of some help! I live in an older home that was poorly renovated…I would like to paint my walls. To do so I started to prep them (clean/sand/scrape flaking paint/spackle small cracks). While scraping some of the flaking areas I noticed I could not identify the wall material. It appears to be very smooth (as in marble smooth) and is a light brown color. One of the tiny areas I scraped turned into a huge section of “naked” wall. What should I do at this point? Do I dare keep scraping? And is the paint peeling because of the extra smooth surface? How do I find out what type of walls they are and what is on their surface? When trying to screw into them, I learned they are very hard and tend to divot where the screw was inserted. Behind this the walls appear to be like cement.
Your walls are probably old cement plaster. You need to carefully remove any peeling paint and prime with an acrylic primer. Add a little water to the primer to help it penetrate any raw areas. You could also use Peel Stop by Zinsser as a first coat of primer.
Peel Stop is a latex penetrating/binding primer that will do a good job to glue together powdery areas for patching and mudding.
This is one on the most difficult surfaces to repaint due to its brittle nature. All that you can do is be careful while prepping and use the primer to help glue things together. The peeling paint is a symptom of the old plaster.