How to approach this rainfall problem from neighbouring roof?

[Fab5Freddy]

I live in a mid-terrace house .The neighbours had a flat roofed loft conversion built a few years ago on the back of the house.

They have a gutter and downpipe on the front of the conversion (ie widow side, away from apex) I noticed a while back that the rainfall on their loft roof wasn't flowing into that, but of the 'back' side and down onto the flashing that they must have installed at the time which is across the line between ours and their boundary on the sloping roof.

As a consequence , the rain fall from all of that side of their house directs down our side, into a gutter and overwhelms it in big downpours (ie yesterday and last night) And by that, I mean it flows over and out of it, onto the wall where the majority f that water flows to the stop end of that gutter.

I dont think this ever happened until the neighbours had extension and I am almost certain it wouldn't happen if their rainfall was directed onto their own side of the divide.

So, the question is - do I just get a roofer to put something down the flashing that 'divides' the 2 roofs , and send it back down their side, or do I tell them to get it sorted?

Not a legal question, more of a 'best practical solution without making enemies'

 

[blup]

Don't see how that could comply with building regs if the fall of the flat roof directs water away from the intended drainage.

The practical solution is as you suggest and cheaper than re modelling the deck, especially if your neighbour s hares the cost.

Blup

 

[Fab5Freddy]

Thanks @blup
Is there an 'off the shelf' type attachment to use do you know?

 

[blup]

You would need to speak to a roofer or builder, sometimes you see domed tiles used to delineate roof boundaries but these may not be consistent with slate roofs.

blup

 

[Fab5Freddy]

You would need to speak to a roofer or builder, sometimes you see domed tiles used to delineate roof boundaries but these may not be consistent with slate roofs.

blup

Cheers, I'll get onto a good roofer