GTV-DR  Manthorpe Double Roman in-line tile ventilator is designed to provide a quick and simple solution to the problems of roofspace ventilation and mechanical extraction / soil stack termination through a Double Roman tiled roof. The profile vent is designed to replace a single tile and maintain an unbroken appearance to the roofline whether used at high or low level. The tortured path through the 4mm louvered grille and internal weathering geometry is designed to maintain a 10,000 mm² of airflow whilst channelling any water ingress out of the vent and on to the roof covering.