We had our cavity insulation done about three years ago, iirc, and we've just noticed something worrying. The installers inject basically chewed up paper, don't they, and make one helluva row in the process! We've just noticed the odd patch of damp on our walls. It has been suggested to us that the stuff that is injected into the walls is itself damp so as to be malleable and could possibly attract more moisture. Does anyone know if that's true? Has anyone else noticed a problem?