Protecto Wrap Co., Denver, offers Rainproof, a 40- or 60-mil-thick peel-and-stick sheet waterproofing underlayment. It can be installed on any exterior grade solid sheathing normally used for roof decking, down to 2:12 pitches. The membrane provides a 2 1/2-inch zip strip on the edges of the bottom release film. The zip strip allows removal of only 2 1/2 inches of the release film prior to removing the whole release backing. This allows for aligning of overlaps, positioning the sheet, even removing and repositioning the membrane in case of error. The membrane is internally reinforced with a strong nonwoven polyester fabric and it has a white reflective topping. It is self-sealing around fasteners.