Hi, I have a stone flag roof, not leaking, loft dry, timbers old but strong. I have just been in loft, shut the loft trap, turned lights off (in order to exclude as much light as poss) and I can see perhaps 20 small areas of light through the membrane...I do intend to get someone to sort this but is it normal on stone flag rood (or roofs in general) and is it an urgent repair
It's quite normal to see points of daylight through an old roof. Even natural slate roofs can experience this.
Even more so with an old flag roof. It's just that the slates are quite coarse, so they don't quite sit down as tightly as a modern slate or tile roof. If you have no leaks, then it's fine.