Cut it to fit your roof if.
Papering a roof valley.
Roof valleys are troughs that discard runoff water where two sections of sloped roof meet.
On the common rafters the plumb cut is marked with a framing square for a 12 in 12 pitch 45 and cut square i e no bevel.
The three methods to shingle a roof valley.
Begin your first row of tar paper with the bottom of the tar paper slightly hanging over the edge of the roof.
Woven valley shingle installation.
Roll out the tar paper along the bottom edge of the roof.
The valleys on many older houses comprise layers of roofing paper which can deteriorate over time.