Hi, having a bit of an issue with an interior wall. Not sure what is causing it but a strip of out wall struggle to keep emulsion on it. No apparent signs of water damage and despite repeated sanding down and painting a few weeks later the pain it crumbly and can be rubbed off with a cloth. It does not appear to bubble Anyone with a help or suggestions?
Prime that area with an oil base undercoat if you have some........ failing that prime with Zinsser Cover Stain.
Age of house? Might help with what could be on wall. Upload picture but you need to make file size smaller for it to upload