其實房客也有責任沒有及時通報漏水，看看老美是怎樣做的

under the terms of a normal lease, they have caused damage to the property. All of my leases had a clause that stated that the tenant must notify me immediately of any issues and MUST NOT NEGLECT ANY UPKEEP OR CAUSE ANY DAMAGE BY NEGLECT.

Under any sensible interpretation the tenant caused this and I would either get them to agree a payment plan or serve a Notice to Quit for damaging the property.