Closed valleys or open valleys.
Roofing a valley with flashing.
Next install a 36 inch wide strip of self adhering bituminous membrane in 10 to 15 foot lengths up the valley.
Fold the top of the flashing over the ridge.
Install an underlayment centered in the roof valley.
To understand what makes a valley either closed or open it is important to understand how a valley is constructed.
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.
Roof one side of the valley running the shingles across it.
Stop nailing 6 inches from the center.
Snap a chalkline 2 to 3 inches past the valley center on the top layer of shingles.
Make sure to cover the gap at the bottom of the raised ridge.
Cut the bottom edge and fold it down over the drip edge.
When properly installed w valley flashing will reliably channel run off water down the roof and into the gutter.
Remember to caulk the underside of the flashing with a sealant.
If eaves flashing is used it should cross the valley centerline each way and be installed before the valley underlayment see eaves flashing discussed in roofing underlayment best practices.
Be sure to check local building codes to ensure you have the proper width for your application.
Then install a non corrosive metal valley flashing of 24 minimum width lap successive sheets of metal flashing a minimum of 12 inches and seal laps.
Now nail this first flashing at both its far ends.
Only nail at the edges with only enough nails to.
To secure the roof valley flashing nail it down carefully.
There are two common methods for completing the flashing of a valley in a shingle roof system.
One of the details that varies between homes is the method of flashing the valley areas of the roof.
To splice the pieces add roofing cement to the lower piece and install the upper piece with at least a six inch.
Recommended procedures of basic valley flashing installation.
Step 6 install the flashing.
Apply an approximately 3 inch.
Ensure ice and water protector has been installed along the valley first.
Then starting at the base of the.
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.
