An apparatus for creating an encased cable seam includes a transportable support frame with a roll of encased cable material supported by a support bar, boom and spindle. Heating units supported by the frame heat the bottom surface of the membrane portion of the encased cable material. The encased cable material released from the roll toward the substrate to create an overlapping seam of the encased cable material on the membrane substrate of a roof deck. The apparatus includes a handle and a roller, whereby the roller presses the encased cable material causing a welded bond as the handle moves the apparatus forward.