I've just raised my garage roof from just below to 150mm above the adjoining garage of my neighbour. Their felt roof used to flap down onto my roof but now I need to direct this felt flap up to my - what in effect will be an upstand. This flap is only 75 - 100mm so I fear it wont quite be long enough to seal against my my roof. I will probably be installing an edpm covering which will flap down "over" this upturned flap of my neighbour.
Will bending their flap from down to the upward direction ruin their felt fabric (its been laid down for 2 or 3 years), what is of the best way to seal it all? Their roof actually slopes in the direction of my garage, somewhat, as a result of some subsidence.