1. The warranty period of the roof waterproof layer of this commercial house is 5 years. Therefore, if the top floor of the purchased building leaks during the waterproof warranty period, it is the responsibility of the developer. Developers have the obligation to repair for free, so they must contact the developers as soon as possible and ask them to repair immediately, so as to avoid the developer delaying beyond the warranty period and causing him to bear the maintenance costs.

2. If the roof leaks due to man-made damage, even during the warranty period, the developer has no obligation to repair it for free, and even if he is willing to pay, the developer often won't repair it. In this case, we can only find the destroyer to provide maintenance services, or the property provides maintenance, so that the destroyer can bear the maintenance costs. Specific maintenance services and costs can be discussed and decided with the saboteur. If the other party refuses to compensate for the loss, it will take judicial channels. If the destroyer can't be found, only the owner of the whole building will share the maintenance cost.

If the roof leaks after the warranty period, the developer will have nothing, because the roof is shared by all owners. If the water leakage is not serious, minor repairs can be made, and then all owners will discuss the sharing of maintenance costs, and after reaching an agreement, they will collect money to find a property to repair it. If the water leakage is serious, such as the roof cracking, it needs to be overhauled. First, apply for overhaul fund. If you apply, you don't have to bear the maintenance fee yourself. If the application for maintenance fund is not approved, then only all owners of the building will share the maintenance cost.