Products / LeakBarrier ValleyFlash

LeakBarrier ValleyFlash is an SBS-modified valley liner: a glass-fiber-reinforced sheet sandwiched between two layers of polymer-modified bitumen, marketed as easier to work than metal and self-sealing around nails, for valleys under composition shingles, shakes, all types of tile and metal roofing. The data sheet prints an approximate 55 mil thickness, 36-inch rolls at 33 lb nominal and says it surpasses ASTM D226 Type I and II, meets the applicable sections of ASTM D6380, passes the ASTM D4869 liquid water transmission test and meets the ASTM D1970 moisture vapor permeability test; the product page adds ASTM D4601 and says it complies with International Residential Code requirements for valley lining material. It is warranted to be free from manufacturer's defects, with no term printed.