The wall is in the downstairs loo/shower room. Shower just for rare guests so hardly gets used. I have a free standing unit against the wall, it has a bookcase thingy and I store lots of my cookery books. We've noticed behind the wall its flaky, no real dampness as such. I've moved all the books out and pulled the unit out a bit so not so near the wall. Our decorator has looked and couldn't work it out. Could the books against the wall possibly cause this? Its an emulsioned wall. The other thing I've done since discovering it when we are at home is to ensure the window is open in there. Most times the door to that room is tightly shut.
Any thoughts/ideas? TIA