Rosin paper
Rosin paper is a heavy duty felt paper used in construction such as underlayment under flooring and siding.
Description and history
Rosin paper is a heavy duty felt paper. It is used in construction such as underlayment under flooring and siding. In building construction, rosin paper is used to reduce air and moisture flow through a wall or floor, create a "friction barrier" so different materials can slip by each other as they expand and contract, keep dust from working down through a floor, and minimize squeaking. Rosin paper is also sometimes used to temporarily protect a work site during construction.Papers from the Middle Ages were sized with gelatine, but the invention of the paper-making machine in the late 18th century demanded a better size resulting in utilization of rosin. Rosin paper may have a polyurethane coating to improve moisture resistance and tearing. It contains abietic acid, and comes in many size rolls up to wide.
Alum-rosin size was invented by Moritz Friedrich Illig in Germany in 1807 and is known to have been used as a building paper by 1850.