The house where I live is over 100 years old. When I first moved in here ten years ago, there was evidence of water damage, but rough repairs had been done and the roof would only leak a small amount very ocassionally, during the heaviest of rainfalls.
The leak is caused by various sections of the roof forming a gulley at the centre of the house. It seems that in exceptionally heavy downfalls, the water must back up and make it's way into the roof, and then somehow it finds it's way through the spot in the pic, which is the doorway into the lounge room. There was some sign of the black marks when i moved in, but it seemed mostly inert. Some of the water must be coming down inside the wall above the door and it emerges through the top of the doorframe.
We are currently experiencing endless heavy rain, day after day, with several more days of similar rain still to come. The other day I woke to find a heap of smashed plaster all over the floor and water dripping in at an alarming rate .... the carpet below is saturated. Even worse is that i have 3 power extension cables crossing the doorway on the floor immediately below the top of the doorframe (this house only has 3 power outlets, so i have to have extension leads to feed power to most of the other rooms).
I estimate that over 40 litres of water have come through the roof in the last three days. Now there is a distinct smell of mould coming from the carpet and no doubt more is forming in the roof and the wall above the doorway.
The landlord is going to send someone to repair the outside of the roof (it will be done cheaply, probably by a handyman/ general maintenance person, but because the roof is metal, it will be slippery so it may not happen for a few days). I am fighting a losing battle trying to get the water out of the carpet (floor is wood underneath), so i can't make any attempts to try to stave off mould. This situation is becoming very stressful and downright unhealthy.