Abstract: A burner has a flame chamber formed by flat upper and lower walls connected by side walls and a front end wall, with a fuel inlet for connection to a fuel source and with an open rear end. A handle is connected with one side of the burner for inserting it between the overlapping layers of a lap joint of fusible roofing sheets for sliding it forward along the joint while flame issues from the rear end of the burner to fuse the overlapping layers together. A hold-down member normally is spaced above the burner, but a device is provided for lowering that member into close proximity to the burner for engaging the upper surface of the upper layer of the lap joint and holding that layer down on the burner as the burner is moved forward. The apparatus may also include a second shorter flame chamber disposed above the front portion of the other chmaber, with openings between them for flow of gas and flames from the lower chamber to the upper one.

Abstract: A burner that has flat upper and lower walls connected by side walls and a front end wall is provided with a fuel inlet for connection to a fuel source and with an open rear end. A device is connected to one side of the burner for inserting it between the overlapping layers of a lap joint of fusible roofing sheets for sliding it forward along the joint while flame issues from the rear end of the burner to fuse the overlapping layers together. Preferably, a roller follows the burner to press the hot layers of the joint together. A second burner may be provided which is opposite hand to the first burner and which is held in an elevated position as long as the first burner is in operating position.