Open Valley Roof Addition

Roof one side of the valley running the shingles across it.

Open valley roof addition.

There are two common methods for completing the flashing of a valley in a shingle roof system. The metal is usually pre painted to best complement the shingles color blend. This metal lining can be made of any. Lay one and two tab shingles as you near the valley so full size shingles will run across the valley.

To understand what makes a valley either closed or open it is important to understand how a valley is constructed. That flashing is left exposed so the roof has visible lines of metal running down the valley. First clean the debris out of the valley including sawdust nails and whatever else is in there. But the stakes are higher for valleys than they are for gutters in a previous video we covered how to flash.

After installing the rafters we still had to extend the porch roof back over the shed roof creating a valley on either side. Open valley shingle installation. Closed valleys or open valleys. Roof valleys are like gutters with a steep pitch but the stakes are higher for valleys than they are for gutters.

Also different architectural styles will use the same type of roof. Roof valleys are like gutters with a steep pitch. When compared to a closed valley and open valley adds an additional layer of lining. The gable roof on the porch addition was framed with a dropped structural ridge supporting the common rafters above.

Again choosing the easy way out we opted to build blind valleys aka california valleys where one. Some homeowners do not like the look of open valleys while others feel the metal accentuates the roof s shape particularly if copper or painted flashing. This allows water to fall from the higher slope to the lower slope and prevents it from going under the shingles to the roof deck. Intricate roofs have many parts that incorporate several of the basic roof designs such as a gable roof sitting atop a gambrel or variations of the gable valley roof design using one or a variety of different types of roof trusses also see our very detailed diagrams showing the different parts of a roof truss.

In a previous video we covered how to flash roof edges before shingling. One of the details that varies between homes is the method of flashing the valley areas of the roof. Snap a chalkline 2 to 3 inches past the valley center on the top layer of shingles. An open valley relies on metal flashing for protection.

After the underlayment is placed a pre bent metal valley lining is installed. In this video we ll flash the valley. Shingle the other side of the valley the same way.