The emergence of specialty underlayment for residential roofing applications developed over many years. Various modified bitumens were developed in Europe in the 1960s and eventually manufactured in the United States in the 1980s. Ray Johnson details this progress in his article, "History and Development of Modified Bitumen."
Initially, modified bitumen membranes were intended for commercial roofing systems but, by the turn of the century, premium underlayment products made from modified bitumen were offered to residential roofing contractors.
Tarco formed a business unit called “Tarco Specialty Products” and launched a comprehensive line of LeakBarrier® branded premium self-adhering underlayments. This market experienced double-digit growth for many years. Contractors appreciated the labor savings, longer exposure limits and durability of these products. Special underlayment products were developed for use under shingles, metal and tiles.
As roofers became familiar with premium underlayments, the idea of a secondary water barrier became increasingly popular. This idea was elaborated in an article “Keeping the Water Out: Self-adhering underlayment can serve as a secondary water barrier” by Steve Ratcliff, which appeared in Professional Roofing magazine, in February ‘09. For the article, Florida roofing contractors were interviewed regarding their experiences using self-adhering underlayment as a secondary water barrier and a case was made for using self-adhering underlayment in this manner, nationwide.