If you are facing the problem of water leakage through the roof, you should contact the professionals and seek waterproofing advice immediately. There are many options available in the market today. Some involve painting waterproof material on the surface of the roof and at the side of the structure where the beams join.
Another more expensive option is removal of the tiling of the roof and redoing it after performing special waterproofing treatment. The expenses involve will depend on the complexity of the task and the area of the roof