I used to see wet water patches on the walls and at times even there happens to be droplets falling from the top. Initially I didn't know why this was happening but then http://www.brothersplumbing.ca/ had come with a solution of coating the roof of my house with the water proof coating which includes repairing the damaged walls by repairing the wet patches area. I am actually confused whether to go with such a coating as this is somewhat an old house, the house might not resist such burden on it :p Would like to hear some ideas from you guys on this.