Who is responsilbe to source a Leak from flat above
I am in the ground floor flat of a 3 storey shared ownership development built in 2003. In 2004 a repair was carried out during the defects period to fix a leak between the bathroom of the top flat which affected the bathroom of the middle flat. Since the initial repair the middle flat continued to suffer leaks from the top flat. In 2008 the leak affected both the middle flat and for the first time my flat. The housing association agreed to fix the problem in all 3 flats outside of the defects period. In 2009 the leak occurred again, this time only between the middle flat down into my flat. The resident in the middle flat maintains this is the legacy of those initial flat leaks. The leak is not constant but is intermitant; the frequency of leak is exactly the same of those originally experienced and explained as being a build up of water which then floods down. The water is coming through my extractor fan in my bathroom.The housing association say they will only get involved if I can produce an independant report that says that the source of the flood does not come from the flat above, but is an internal building problem. I have contents insurance and the housing association has building insurance, they say we are responsible for the pipework within our flat. Where should I start, do I have to pay out for an independant plumber to access the situation or would my contents insurance pay for the initial investigations?