Liability for leak damage from hidden pipe in purpose-built flat block

[DrapeyDreamer]

Mumsnet was incredibly helpful when I property issues so I'm posting on behalf of my sister, as she's quite passive unfortunately.

She owns a flat in a purpose built block (it's about 20 years old and she's owned and lived in her flat for about 10). On Friday evening, she received a knock on the door from the owner of the flat below (let's call him Bob) to say that there had been a leak and a quite substantial one. There was no signs of water damage in her property.

She called out her plumber on Saturday morning who investigated quite thoroughly and couldn't find the source of the leak. Bob then sent round his plumber who was quite sure it was a leak behind her toilet and proceeded to hack the tiles around the toilet and cause damage. Bob himself confirmed that the job was badly done as they tiles were destroyed. However no sign of the leak. Meanwhile Bob's flat was getting worse and water leaking was starting to go into the flat below (which he also owns).

They found a third plumber who did leak detection to attend on Monday who spent several hours investigating and after cutting several holes, eventually localised the damage to eroded copper pipes in her walls. As these are supplying water to her flat, she's responsible for maintaining them, however am I right in thinking there's no negligence? It's poor workmanship of the block developer and with no signs of leak within her flat, would have been impossible for her to identify a leak.

She contacted her management company who said that the blocks insurance excess for escape of water issues is £2500 (!) increasing from £500 last year as there been a number of claims in the building last year. However, when she looks at the insurance policy that's been on the portal from last year, it still says £500.

Another potential issue is that Bob's flats are also being used as Airbnbs (they've been used as Airbnbs for the last few years) which are in breach of the lease. There has been quite a lot of damage to flat directly below, but it can be argued that they left it quite late to inform her?

Would she liable for the full repairs? There's no negligence technically on her part?

This is why I really don't like flats!

Contents insurance covers this. If Bob has valid contents insurance he should claim. The insurance company may then decide to
claim against your sisters insurance or the building insurance. It’s a bit like when you have a car crash. You contact your insurance about your car and the other driver contacts their insurance about theirs and then the two insurance companies liaise with each other

Thanks, that's helpful to know!

This happened to us recently in one of our flats. The entire cost was our responsibility including making good the damage to the flat below ours.

In order for your sister to be liable there needs to be negligence on her part and from the limited information given it doesn't appear that's the case.

The block insurance should be covering this.

Thanks! Was there any negligence on your part? What caused the leak?

I would have expected it to be primarily the buildings insurance you need to claim on (eg for redecorating). Contents insurance would just cover carpets, TVs etc. If your lease states you are responsible for.maintaining that pipe then I'd expect you to be responsible for the excess. Though I'd perhaps start by offering to split the excess with the flat below on the basis the flat had been Airbnb'd. How old is the property?

Thanks! It’s about 20 years old. The issue is that the excess is so big, so if the flat below starts to claim substantial damage, she could be liable for a considerable amount.

If the leak was caused by , for example a screw being put through the wall or a nail hitting the pipe and corroding, she might be liable. Otherwise it is for Bob and the insurers to debate.

Thank you! I’ll recommend that she refrains from paying for anything besides the cost of the plumbers