Abstract: A roofing underlayment comprising a carrier substrate included a felt mixture and a binder mixture, and a volume of asphalt flux saturating the carrier substrate. The felt mixture may comprise between about seventy-five percent and about ninety-five percent by weight corrugated paper/cardboard fibers and between about five percent and about twenty-five percent by weight fiberglass fibers. The volume of asphalt flux may comprise between about twenty-five and fifty percent of a total weight of the roofing shingle underlayment and may saturate the carrier substrate at a saturation percentage between about thirty and about one hundred percent. The binder mixture may include a mixture of alum and rosin having a mixture ratio by weight of alum to rosin in a range between one to one (1:1) and four to one (4:1).