Your choice of valley installation method is critical because when improperly installed valleys are risks for serious leaks.
Roofing procedure valleys.
Apply an approximately 3 inch.
A roof valley is formed where two roof slopes meet.
Of the shingle tabs where the bottom edge of the tab meets the top of the cutout.
The lowest of these valley shingles is cut back at an angle in line with the lowest course line.
Use four roofing nails per shingle as indicated on package instructions six nails in high wind areas.
Stretch it about 12 inches across the centerline.
Recommended procedures of basic valley flashing installation.
Draw a 2 inch self stick flashing down the center.
Once this course is laid you can begin snapping horizontal chalk lines up the roof to ensure straight rows.
Roof installation how to shingle a valley hd by roofrepair101 more about roofing at.
Make sure to expose 5 in.
Water collects in a valley to flow off the roof.
Away from the valley center just as i did with the closed cut valley.
The reason that many roofers like an open valley is that they feel that tree leaves and needles will more easily slide down or wash down an open valley when it rains.
Install an underlayment centered in the roof valley.
When i ve finished shingling the first roof plane i snap a chalkline 2 in to 3 in.
Next i smear roof cement a couple of inches away from my snapped line.
Woven closed cut and open.
Then i install a line of shingles up the valley with the top edge aligned with my snapped line.
Also apply cement to attach the top layer shingles to each other see steps 5 and 6 in open metal valley above.
This video demonstrates the proper installation technique for installing roofing valleys.
Roofers on the other hand often prefer an open valley because they feel it is more practical.
Fasten the shingles about 6 inches away from the centerline on both sides.
Apply two beads of roofing cement to attach the top layer shingles to the bottom layer shingles.
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.
Start by laying all shingles on one side of the roofing and stretch it across the valley.
The open woven and closed cut methods are demonstrated.
In the past i ve used several different methods to prepare a valley including lining the valley with aluminium coil flashing or roll roofing and even cementing together layers of 30 felt paper with asphalt roof cement a messy job.
Architects often prefer closed valleys to open valleys as they feel that it gives a home better architectural appeal.