Modern Membrane. IB-3 StormStopper is a self-adhering (50-mil-thick) mineral surface underlayment that can be used to protect trouble spots like valleys and rake edges or the entire roof. Made with a rubberized asphalt adhesive that self-seals around fasteners and projections, the liner separates easily and splits in the middle to simplify valley installations, says the maker. It comes in 3-foot-by-67-foot rolls. The company declined to provide pricing. MFM Building Products, 800/882-7663, solutions.mfmbp.com.