Leak from cracked pipes below my unit onto ceiling of unit below

[csaba81]

I own a unit in Chiang Mai which has been unoccupied for the the past 10 years. Recently management informed me that the ceiling of a bathroom unit below had been damaged due to a cracked drain pipe underneath my unit which services my apartment only. I was told that if I used their contracted plumber, the repair would cost 5,000 plus another 2,000 to replace and repaint the ceiling of the unit below (parts and labour).

 

I noticed that my own unit also has stains in the ceiling in the same place, and management conceded that the problem has affected many units. My own unit has the master turned off and I checked thoroughly for any running water or leaks. Everything is bone dry. Management explained that what was happening was that water from the main vertical downpipe (common property that services all units) was 'back-splashing' into the horizontal pipe that services my unit and then out the crack. So that's apparently how water can be leaking from an unoccupied unit with the mains off. 

 

Questions:

 

1.  If water can 'back-splash' from a main downpipe, isn't this a flaw in the plumbing design? I concede that if my unit was occupied then water would likely be coming from my unit also. So it seems to me that the cost here should be shared between me and common property.

 

2.  I don't see myself as responsible for the repairing the ceiling below. I was told that the unit below had been occupied for many years so the problem should have been reported at the first signs with a little paint (after the leak had been repaired of course) but the owner waited until much of the ceiling was stained and warped. Perhaps the price of a can of a paint as a goodwill gesture?

 

3. Is it reasonable to ask for some kind of guarantee that the repairs needed for the pipes above my unit will be covered before agreeing to pay for any repairs?

 

4. Does the 5,000 for the pipe repair seem reasonable?

 

Am I wrong or being unreasonable? informed feedback appreciated.

[treetops]

For me, £160 GBP (I'm British) to put right an issue in a condo which I'd neglected for 10 years would be a small price to pay.  Not worth getting into a debate about, although number 3 is probably a good move and actually insisting on it being done at the same time.