Different Types of Roof Ridges & Valleys
Sloped roofs are complex structures, and when there's more than one slope involved, the structure gets even more complex. Intersecting gables, hip roofs, dormers and other roof structures create ridges and valleys. Ridges are the external peaks where two sloping planes meet, and valleys are the internal intersections of sloping planes. Both ridges and valleys require special attention from roofers.
The ridge beam is the main supporting beam that runs along the peak of the roof where the sloping planes meets. It forms the highest point of the roof, and it runs from one end of the roof to the other, either between gables in the case of a gable roof or between hip rafters in the case of a hip roof. The ridge beam is covered by ridge shingles, which cover the ridge and the top edge of the final courses of shingles on both slopes of the roof.
Hip Rafter Ridge
On a hip roof, hip rafters run from the eaves at the corner of the building to the ridge beam and create the slope of the hips. These rafters form a ridge that slopes from the ridge beam down to the corner of the roof. Like the ridge beam, this ridge is also covered by ridge shingles.
Woven and Closed-Cut Valleys
In a woven valley, sometimes called a laced valley, alternate courses of shingles are overlapped from one plane of the valley to the other, resulting in a woven appearance. A closed-cut valley is similar to a woven valley in that shingles are laid across the valley. In a closed-cut valley, however, the shingles overlap the valley only in one direction, from one plane to the other. The shingles from the second plane are trimmed in a straight line where they meet the valley and overlap the shingles from the first plane.
Unlike woven or closed-cut valleys, open valleys have no shingles crossing the valley. Instead, the shingles on both planes of the roof that form the valley are cut back from the valley, and the valley itself is protected by a metal flashing. Shingles on both planes overlap the flashing. The National Roofing Contractors Association recommends that the flashing extend eight inches on either side of the valley and that the shingles overlap the flashing by four inches.