The valleys on many older houses comprise layers of roofing paper which can deteriorate over time.
Papering a roof valley.
To achieve a woven valley installation a roofing professional lays shingles in the valley and weaves them together.
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.
Begin your first row of tar paper with the bottom of the tar paper slightly hanging over the edge of the roof.
Roof valleys are troughs that discard runoff water where two sections of sloped roof meet.
The valley rafter is marked for a 12 in 17 pitch and then cut with a double bevel to fit into the ridge intersection.
Roll out the tar paper along the bottom edge of the roof.
Cut it to fit your roof if.