Rosin paper is a multi-purpose building paper used underneath hardwood floors as an underlayment. It is used as a moisture-barrier and it allows the wood floor above it to breathe. The paper is installed just before the wood flooring and comes in rolls of various lengths. Installing rosin paper is a critical element in the installation process of any hardwood floor.
Measure the size of the room to determine how much rosin paper will be needed. Run a tape measure across the length and width of the room. Multiply the two measurements to get the total square footage of the area.
Inspect the sheathing already on the floor to make sure it is in good shape and there are no nails sticking up. Hammer down any that are sticking up. Sweep up the subfloor with a broom and pan to remove any dust and debris that may have accumulated.
Pull off any base molding or quarter round along the bottom of the wall. Slide a small putty knife underneath the molding and pull it up. Set it aside for later use. Unscrew and remove the door threshold with a drill.
Roll out the rosin paper beginning in the bottom left hand corner of the room. Spread it out and insert a staple every 12 inches through the paper and into the sheathing underneath. Attach a staple around the perimeter of the rosin paper and in the middle to properly secure it to the sheathing.
Move to the end of the room and cut the paper to size with a utility knife. Set the second layer directly above the first and overlap the two by four inches. Attach the two together with staples and continue around the room until all of the sheathing has been covered with rosin paper. Inspect the area to make sure there are no staples sticking up and that everything is covered to the corner of each room.