rosin paper

plural rosin papers

1. uncountableusuallybusinessA heavy-duty felt paper used in construction as a layer under flooring and siding.

   1 more example

   This inexpensive paper is sometimes called “red building paper” or “slip sheet paper.” It's traditionally been used between house siding and wall sheathing, and beneath wood flooring. With the advent of house-wrap products, the use of red rosin paper behind siding has nearly disappeared, but it's still widely used under flooring as a vapor barrier and a sound-deadening layer.

   2010, Joseph Truini, Installing Floors

   Synonyms: brown rosin paper, building paper, red building paper, red rosin paper, slip sheet paper