My first attempt to do some decorating, so take it easy on me :)
I have been taking down the wallpaper in my spare room, which was randomly wallpapered on one side only. Now I know why! I've found some sort of material sticking out of the wall, looks like its been used either to patch a hole or maybe it's some sort of damp proofing? It doesn't feel like rock, but it is hard.
Does anyone know from the pictures what this is and what I should do to get rid of it? As it sticks out and is rough, I can't paint over it.
Thanks,
Mike