torching

Looking at a 1920s roof with no felt - some tiles (flat and ridging) were replaced after storm damage a while ago, but none of the replacements had the torching put back. There are some big gaps and it’s very draughty - I was thinking of trying to line it across the rafters with a membrane...

We have a 1930s house with a tile roof without any felt. It has lime mortar torching which falls constantly. We only use the loft for storage but I'd like to stop everything getting covered in the mortar. I have a few questions as I've had some existing advice from roofers: Is it ok to have the...