I'm renovating my house. I'm stripping it back to the bare walls. The gable walls are stone and the others are poured concrete. These walls are very cold and quite damp. I'm going to be putting up new studwork throughout and using Earth wool insulation for the walls. I don't suppose it's a great idea to let this insulation touch the exterior walls as it would get damp and the damp would end up in the stud wall. My question is what barrier should I use between the exterior walls and the studwork to keep the insulation from coming into contact with the damp exterior walls? Thank you.