hi we are living in a mid terrace.our neighbours have replaced all the guttering front and back about 2 years ago.however last yr we had a leak they have not been joined properly.now it is happening again.my issue is why is their guttering running along onto our side of the roof and the join is consequently over our back toilet window. it looks to me that they replaced thier own but put the join over our side.surely like all the other houses it should be where our 2 houses meet.