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How to install flashing on roof valley.
Snap a chalkline 2 to 3 inches past the valley center on the top layer of shingles.
Install synthetic roofing underlayment or felt paper according to manufacturer specifications and then install the first piece of valley flashing.
Shingle the other side of the valley the same way.
Apply an approximately 3 inch width of asphalt roofing cement along the sides of flashing and embed shingles in mastic.
W type valley flashing is more rigid for handling so it stays straight and it stops waler rushing down one side of a roof from rushing back up the other side.
Drip edge metal valley flashing dormer chimney and kickout flashing are types of roof flashing that shed water away from the connections between roofs walls chimneys and other building assemblies.
Lay one and two tab shingles as you near the valley so full size shingles will run across the valley.
Step 6 install the.
Roof one side of the valley running the shingles across it.
In this video i show you how i do the valleys on a shingle roof.
Remember to caulk the underside of the flashing with a sealant.
Then install a non corrosive metal valley flashing of 24 minimum width.
Many roofers cut the shingles across because they say it s safer.
Install valley battens on both ends of the roof valley then attach first flashing 3 4 inches over the roof flange and another 3 4 inches over the fascia if any is present.
Stop nailing 6 inches from the center.
Architectural shingle installation is especially critical in roof valleys where iko recommends an open valley installation.
Lap successive sheets of metal flashing a minimum of 12 inches and seal laps.
Install an underlayment centered in the roof valley.