We have a 1930s house where the roof is just tiles straight onto the rafters ie no felt. We really need to put something up under the actual roof, mainly to stop the dust/etc getting in. My huband is keen to put up that foil/bubble roll stuff by putting it over the rafters. I'm concerned that this will mean that any moisture that gets in will have no where to go and potentially cause damage to the wood. Anyone with any suggestions/advice please?