An open ended, flat spiral belt (10) is joined at its ends on a roll (12) to form an endless cover. A spiral belt is fitted with a zipper assist (24) in the seam area to facilitate the joining of the spiral belt on the roll. One part (26) of the zipper assist (24) is removably attached to one end (40) of the spiral belt with the other part (28) of the zipper assist being removably attached to the other end (42) of the spiral belt. When the two sections (26, 28) of the zipper assist (24) are zipped together, they pull the two ends (40, 42) of the spiral belt (10) together, allowing for interdigitation of the spiral loops of the spiral belt, which then forms a channel for the introduction of a seam wire (60). Once the spiral belt (10) is seamed on the roll, the zipper assist (24) is removed and the roll (12) is set in slow motion at about ten revolutions per minute. The entire fabric is subjected to application of heat from a hot air gun to set the spiral belt, now in the form of a spiral shrink sleeve.