Intersecting Roof Valleys

Lay one and two tab shingles as you near the valley so full size shingles will run across the valley.

Intersecting roof valleys.

The gable roof on the porch addition was framed with a dropped structural ridge supporting the common rafters above. For roof pitches less then 6 per foot the flashing extends at least 12. Snap a chalkline 2 to 3 inches past the valley center on the top layer of shingles. An unequally pitched valley rafter is laid out in the same way as the unequally pitched hip.

Fold the top of the flashing over the ridge and nail it off every ten inches or so along the outer edge of the flashing now this valley will carry water off the roof and away from the house. Where two gable roof lines meet the intersection forms inside corners called valleys. Roof one side of the valley running the shingles across it. Gable and valley roof.

Again choosing the easy way out we opted to build blind valleys aka california valleys where one intersecting roof is built on top of the other. To splice the pieces add roofing cement to the lower piece and install the upper piece with at least a six inch overlap. For roof pitches of 6 or more per foot the flashing extends at least 9 under the roof covering on each side. How to install a valley on a vicwest metal roof.

Repeat the process on the other side of the hip using the pitch of the hip for the secondary roof 9 5 8 18 13 16. The main difference between the two is that valley rafters sit on inside corners while hip rafters sit on the outside corners. It s also known as a cross gable roof since the home has a cross footprint. Interestingly you can mix and match roof styles when building a gable and valley roof designs for a cross footprint home.

The gable and valley roof is a very popular roof design. Stop nailing 6 inches from the center. Intersecting roofs using a closed valley must have the same slopes so that the shingle butts line up at the valley intersection.