Dry rot insurance claim - whose fault?

[WillPenn]

We live in a flat. We are having our bathroom renovated. Once the false ceiling was ripped out we saw dampness on the real ceiling that had been hidden below. It turns out there is dry rot caused by bath/shower in flat above. There was a leak of actual water once but this stopped after a complaint to the landlord.

The landlord who owns the flat above (whom I don't trust) intimates that we will both have to claim on our insurance for the repair as it is our ceiling as well as his floor. However, the problem has not been caused by us. It is clearly caused by his leaking bath. Why on earth should we claim on our insurance and pay the £550 excess that comes along with this?

Lawyers/anyone - what do you think? Our insurer flaky and said it is "up to us" to sort out liability with the landlord above!

Dry rot is not an insured risk in buildings insurance. I think therefore you will have great trouble claiming on your insurance. The same goes for the people above. However buildings insurance does include third party liability, so you may be able to claim under that by taking your neighbours to court, but your own insurance won't help you to do this. However a claim in the Small Claims Court shouldn't cost very much to bring and is quite straightforward and you would stand a good chance of winning, but you would need a surveyor's report stating that the cause of the dry rot was the shower of the flat above.