Place a piece of sheet metal under the shingles to make sure you will not damage the flashing.
Shingle roof valley installation.
To shingle out of the valley with laminated shingles lay a shingle down as a gauge and mark the corner at the bottom left and top right of the roof.
How to do it determine cuts.
Snipping off the corners of.
This video demonstrates the proper installation technique for installing roofing valleys.
Ensure ice and water protector has been installed along the valley first.
Others start with a 3 inch wide.
To secure the roof valley flashing nail it down carefully.
The open woven and closed cut methods are demonstrated.
I then move the shingle to the uppermost course on the roof plane line up the mark on the shingle with the valley center and again mark the corner.