How To: Shingle Roof Valleys
GAF- Mastering The Roof (chapter 12)

This video demonstrates the proper installation technique for installing roofing valleys; the open, woven, and closed cut methods are demonstrated. Valleys are a prime leak area, so it’s important to be careful.

Valleys are one of the areas that true professionals take their time in doing right. The average valley gets loaded up with a substantial amount of water, and can get backed up with ice and snow in colder areas.

There are three methods for installing valleys including the open, woven, and closed-cut methods.

First, we’ll look at the woven valley. The woven valley should only be used with 3 tabs or Slateline shingles.

This technique should not be used with GAF laminated shingles because of their thickness.

So we’ll install a Woven Valley with three-tab shingles.
Remember, valleys are a prime leak area, so it’s important to be extra careful.
That’s why we require the use of Weather Watch or Storm Guard self-adhering leak barriers in all valleys to qualify for the Golden Pledge Limited Warranty.

The woven valley is a very waterproof valley because it leaves no exposed openings and because the two sides of the valley are usually blended together seamlessly. The first step is to install Weather Watch or Storm Guard leak barriers down the valley. Then lay Deck Armor, Tiger Paw, or Shingle-Mate deck protectors on the deck, Even if water does get blown in under the shingles, the Leak Barriers and Deck Protectors will provide an extra layer of protection.

The woven valley shingles are applied simultaneously on both sides at the intersecting roof surfaces. Bring the first course along the eave up to and over the valley with the last shingle extending a minimum of twelve inches onto the intersecting roof.

Now, bring the first course on the intersecting roof along the eave and extend it twelve inches across the valley and over the previously applied shingles.

Press the shingles into the valley and nail them in place. Make sure that you press the shingles far enough into the valley to prevent bridging. Use normal nailing methods except that no nail should be within six inches of the center line of the valley. Two nails should be placed at the end of each shingle crossing the valley.

.Continue by applying additional courses of shingles in the manner just described.

The closed cut valley is popular in many parts of the country and shows the aesthetic appeal available with asphalt roofing shingles. Now how do you create this valley with laminate shingles? Simple.

First lay Weather Watch or Storm Guard deck protector in the valley.

Bring the first course of shingles along the eave and across the valley on to the roof plane that has the lower slope or lesser height. Starting on this side allows the largest volume of water to come over the cut and not into the cut. The first course is the only course that is woven with the intersecting roof surfaces.

Now, apply shingles, assuring that you extend at least 12 inches past the intersecting roof. Don’t make a joint in the valley. If a shingle falls short, insert a one- or two-tab section or twelve to eighteen inches of laminated shingle in the row so that a full shingle extends over the valley.

Press the shingles tightly into the valley. Make sure that the shingles lay flat enough so that no bridging occurs. Secure the shingles at the valley using normal nailing methods, but remember – make sure there are no nails within six inches of the valley line. This will ensure there is a 12″ minimum nail free zone in the center of the valley. To ensure proper fastening, two nails should be placed at the end of each shingle that crosses the valley.

.Continue to apply succeeding courses in the same manner.

Next, apply shingles to the un-shingled side. Make sure that the shingles extend past the centerline of the valley so that they can be trimmed properly in the next step.

_Trim the shingles as you install them using a chalk line to insure a neat installation. Crop one inch on a forty-five degree angle from the upper corner of each end shingle as you install. This will direct any water back into the valley.