This is a real rookie question, but the shower in our loft conversion has leaked into the room below - when we took off the wallpaper the wall below it is damp and there is a hole where the wall meets ceiling. It leaked before and we got it fixed, but it must have started again and the water has found another route down. We've got someone coming to address the leak, but who should I call to assess the damage to below and repair the ceiling? Is it a decorator/builder? I don't want to just paper over the cracks (literally!). Thanks.