Open Valley Roof Addition

After the underlayment is placed a pre bent metal valley lining is installed.

Open valley roof addition.

Roofing shingles are installed then cut and sealed where they overlap the metal channel. Roof valleys are like gutters with a steep pitch but the stakes are higher for valleys than they are for gutters. To understand what makes a valley either closed or open it is important to understand how a valley is constructed. There are two common methods for completing the flashing of a valley in a shingle roof system.

Shingle the other side of the valley the same way. For an open valley a sheet of metal usually steel sometimes copper is fastened to the roof deck. An open valley relies on metal flashing for protection. The gable roof on the porch addition was framed with a dropped structural ridge supporting the common rafters above.

Open valley shingle installation. Also different architectural styles will use the same type of roof. Stop nailing 6 inches from the center. Closed valleys or open valleys.

After installing the rafters we still had to extend the porch roof back over the shed roof creating a valley on either side. 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. That flashing is left exposed so the roof has visible lines of metal running down the valley.

The metal is usually pre painted to best complement the shingles color blend. Lay one and two tab shingles as you near the valley so full size shingles will run across the valley. 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. When compared to a closed valley and open valley adds an additional layer of lining.

But the stakes are higher for valleys than they are for gutters in a previous video we covered how to flash. Roof valleys are like gutters with a steep pitch. Roof one side of the valley running the shingles across it. Again choosing the easy way out we opted to build blind valleys aka california valleys where one.

In a previous video we covered how to flash roof edges before shingling. 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. In this video we ll flash the valley.