The valleys on many older houses comprise layers of roofing paper which can deteriorate over time.
Papering 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.
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.
Cut it to fit your roof if.
Roof valleys are troughs that discard runoff water where two sections of sloped roof meet.
Some homeowners prefer the consistent look that a woven valley provides.
The three methods to shingle a roof valley.
Woven valley shingle installation.