Shared felt roof problem with neighbour

[sanity69]

Got a leak, Got a tarpaulin up for now to slow it down some. So its a flat felt roof shared with neighbour, problem is the felt wasn't done right in the first place no drips into gutter it was stopped at edge of deck and so over time the water has affected the front all the way across the gutter edge. The roof deck is 2cm thick cladding. I wanted to replace the whole roof including neighbours but he doesn't want his side done. Problem then is his side will continue to fail and because its cladding they inter-connect thus water will creep our side through the timber. I need to some how divide his roof from ours including timber. I cant check if the support joists/beams stop in the middle on the dividing wall or they are full length from his house to mine until i strip the roof. The cladding luckily though is front to back not his side to our side. Any suggestions on how to possibly divide the roof at timber level as i will have to overlap the felt as well, saying that another problem is hes patched his side with shed felt and bitumen cold sealer and the water runs mostly to our side.What a complicated mess i know.

 

[datarebal]

the problem here is you will get your side done and then he will blame the roofer for making his leak when it was already knackered.. I had a colleague that fell for that

 

[Notch7]

If the fall is parallel to the dividing wall I would think you could probably put in an upstand and separate your flat roof from his -its possible to do in most roofing systems but im not sure in felt......there is an awkward detail where the gutter drip goes.

Whatever you do, somewhere you will need to join old felt to new, Im not sure how easy how easy it is to make that a robust join.

 

[^woody^]

Form a kerb which will need to be on your side of the boundary, then flash (/felt) over and down on to his side to seal it