Modern super insulated houses have mechanical ventilation of so much per
hour, but old houses and roofs depend on air passing through, which is a lot
more on windy days. So how big the ventilation holes in roof are is a
balance, I can accept a few days in maybe still and foggy conditions there
will be condensation, which will dry out on the 99% or more normal weather
days. Similarly after lots of rain from a certain direction theres rain
inside my attic, which will evaporate away when the weather changes. wood
only rots when its been wet for many weeks. But ifg you have lots of
showers, and overboil lots of cooking, and block up your house airvents (as
some tenants do) then there will be condensation everywhere, hose and attic.
PS STOP SWEARING - WHAT YOU SAY IS WHAT YOU ARE
I have a super insulated house and never experience condensation.
There is no mechanical ventilation.
The roof space has ventilation holes that allow through ventilation.
If you are experiencing wet in your roof in windy conditions it's likely
water is being driven "uphill" under the roof tiles. ie there is
insufficient overlap for the "slope" of your roof.
Wood rots a lot easier than that. Once wet it might take weeks to dry out.
Long enough for rot to set in.
And if you get dry rot, then drying out won't help at all.