Abstract: A method for production of a breathable roofing underlayment comprising a sheetlike carrier (1), for example a base nonwoven, which by a membrane (2) applied to the carrier (1) is airflow—and water—tight yet pervious to water vapour, wherein the membrane is a hotmelt adhesive film (2) applied hot directly to the carrier (1), the method comprising the steps of applying continuously to a carrier structure, for example a base nonwoven (1), a membrane (2), wherein the carrier (1) has directly applied thereto a slot-extruded film (2) of a hotmelt adhesive.