Holes in roofs seem to just be waiting for the weather to turn. Noticed a few in my gables which is nice.
Time to get cleaning
A little tip; Hibiscrub is a safe and very effective way of stopping and getting rid of most moulds and fungal infestations. It's Chlorhexadine, available in equine suppliers for less than a tenner for 500ml, mix it 50/50 with water and use a cheap mister/sprayer thingy to soak the stuff, leave for 20 - 30 mins then wash as normal.
This treatment has saved my bacon more than once with kit, leather and infested wood when I've let stuff get damp in the past.................Give it a try!