On our roof, a rubber mat (Raw HP 530) has been laid but without a triangular strip at the fascia boards. The person responsible for the roofing claims it is not needed. The rubber membrane is anchored at the top of the fascia. The membrane is stretched with varying tightness against the board, creating a gap with the sheathing exposed up to the ridge. Perhaps a novelty, but how well-tested is it? The roof should last for 30 years.
