We have a lead lined, concave roof on a bay window. The roof itself has a small drain.
Inside the house, below the bay window we have a small leak that occasionaly appears when it rains. I have attempted to seal up the roof using bitumen tape and most recently painted with elastomer based roof seal paint (really thick rubbery paint).
The leak is much reduced. However there is still a small one, sometimes.
Any tips on finding the source of the leak in such a situation ? My current plan is to go up with bucket of water and assess possible holes by pouring water in them and waiting for any leak (there was nothing particularly obvious last time I was up).