Abstract: The invention relates to an apparatus for the heating of roofing material. The apparatus comprising: air supply means (86); an elongated tubular combustion chamber (10) with a first end (11) and a second end and having a wall (30) surrounding a longitudinal axis (A) of said combustion chamber (10) and including an exit for hot air at said second end (12) and at least one air entrance (50) near said first end (11) for delivery of a primary air flow. A burner arrangement is disposed essentially centrally within said combustion chamber near said first end. The burner arrangement comprises means for injection of fuel (88) and means for ignition of said fuel (80). The first end (11) of the combustion chamber being essentially air-tight, and said at least one air entrance (50) being located in the wall (30) of the combustion chamber (10) near said first end (11). The air entrance (50) comprises means to produce a helical current of air around said longitudinal axis (A) of the combustion chamber (10).

Abstract: A roof vent (8) comprises a conduit having an open entry end adapted for being arranged in sealing communication with an aperture in a roof surface, and an exit end spaced from said entry end, shield means (31) adapted for preventing entry of rain into said conduit, a valve assembly for controlling flow of air or gas, said valve assembly comprising a valve member (13, 22) adapted for opening to passage of air or gas when the pressure at the entry end exceeds the pressure at the exit end and adapted for closing on other conditions to prevent back-flow of air or gas, and thermostat means (27) adapted for opening said valve member to bidirectional passage of air or gas when the temperature at said thermostat means exceeds a predetermined level.