The leaking water pipe on the third floor soaked the roof of my house. Is it a property owner or a developer? Or is the third floor owner responsible?

The property is definitely not responsible. Indoor facilities have nothing to do with property.

Judging from experience, it should be that residents have a greater responsibility. Sewer pipes are generally installed in the whole pipe, and will not be damaged without external force. At present, houses are basically rough houses when they are handed over, and residents will inevitably encounter hidden dangers of pipelines when decorating, especially when installing floor tiles and walls, and it is easy to hurt pipelines when constructing around pipelines. Most of the existing sewer pipes are made of PVC, which is not as strong as the former cast iron pipes. When they are hit by wall tiles and floor tiles many times, they are prone to cracks and may be fine in a short time. However, as the service date becomes longer, leakage may occur in the dark part.

You'd better consult with the developer's representative and the residents on the third floor to open the decoration inspection on the spot. Who is responsible, who will bear the cost.