Neighbour's property damaging my property - help!

hypermobility

Hi everyone, I'd appreciate some advice on an issue that's arisen with my new flat, which I completed on and moved into last week.

One of the bedrooms has a fairly significant damp problem which has affected the plastering and the wallpaper, and which is ongoing. Based on the location of the damp, and on the fact that the Home Report flagged up possible issues with the flashing on the gable end and the chimney (it's top floor), I assumed that it would be a question of replacing the flashing and possibly getting some patching done on the roof. I was even prepared to spring for reroofing if necessary (there are six flats in the block and the costs split six ways wouldn't have been too prohibitive). Anyway, I had a roofer come out to take a look a couple of days ago. The good news is that my roof looks pretty sound, though the flashing and the guttering could do with some work. The bad news is that the property that adjoins mine and shares a wall hasn't been tied in properly, and there are gaps in the brickwork, which are almost certainly at least part of the reason for water getting into my property. The roofer was pretty clear that it was an issue with the next-door property, not with mine (which might explain why it wasn't mentioned on the Home Report), but it's obviously having a fairly major impact on my flat.

So...what now? I have been told that there is absolutely no legal obligation for my neighbours to have the problem with their brickwork fixed, even though not doing so is damaging my property (I find this pretty surprising and will definitely double-check to confirm this!), so I am going to have to take a very careful, persuasive approach. To further complicate matters, the flat in question is for sale, and has been for quite some time (for more than twice what I paid for mine, although it's identical - it's been done up, but even so!), so I doubt they're going to want to take on lengthy, extensive and costly building work at this time (my roofer estimated it would cost my neighbours in the region of £8-12,000 to have the problem fixed). My impulse is just to go round and talk to them, but I'm aware that once I raise the issue they will then 'officially' know about the problem and have a legal duty to inform any buyers of the problem, so drawing it to their attention may not make me particularly popular. I can't see that there's any way they're going to get a buyer for the property at the price they're wanting in the current market, and even less so if they're selling it with costly building works needing doing to it. I feel like I really need to handle this very carefully, otherwise I risk making the situation worse. Should I write a letter? Involve a lawyer?

Any advice would be much appreciated!

(Oh, and I'm in Scotland, in case that makes any difference to the legality of the situation!)

G_M

Yes, I guess Scotland might make a difference. However, there seem only two ways to resolve this:
1) amicably. Discuss the problem with neighbour and reach a friendly agreement (presumably that he fixes the underlying problem and ideally also covers the cost of repairing your own property's damage)
2) Legally. You sue for damages and at the same time seek an injunction requiring him to repair his own property.

1) requires care, diplomacy, and a sympathetic neighbour!
2) requires legal advice AND surveyors reports to prove your case.

Will your insurance cover this (either the repairs to your property and/or pursuing the neighbour)?
Do you have legal cover (either as an add-on to your property insurance, or via employer, union, or stand-alone insurance policy)?

Option 3 is obviously a variation on 1) - reach a compromise by offering to contribute to the cost as an incentive to the neighbour to do the work without having to resort to option 2)