My family lives on the top floor, and the roof has been leaking for several years. What should we do?

Don't let the property go to the maintenance fund to do that thing. They are all the worst waterproof materials, and they can be used for one year at most. I'll introduce you to a waterproof material, Qinglong brand. Used this year, and it's not expensive. It's a waterproof paint that you can brush yourself. This is high technology. It doesn't matter how hard it rains. It will last for ten or eight years.