Abstract: A foam suitable for use in roofing systems is provided. Roofing membranes comprising the foam have superior flowing properties at high temperatures without sacrificing low temperature performance. A particular useful roofing membrane comprises an upper surface layer, a reinforcement layer, and optionally a lower self-adhesive layer, wherein expanded microspheres are provided in one or more of said layers in an amount of between 0.01 and 10% based on the total weight of the roofing membrane. Moreover a method of making roofing membranes is provided.

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 method of manufacturing a bituminous coating sheet, wherein a bitumen-impregnated core material provided with a layer of backface bitumen is caused to be in contact with one or more rotating bodies during the manufacture. A slip material dispersed/emulsified or dissolved in a liquid is applied onto the bituminous backface layer on the side that is to be brought into contact with a rotating body; and that the liquid is evaporated prior to contact with the rotating body; and that subsequently a further bituminous layer is applied onto the side which is provided with said slip material.