But the stakes are higher for valleys than they are for gutters in a previous video we covered how to flash.
Open valley roof addition.
In a previous video we covered how to flash roof edges before shingling.
Closed valleys or open valleys.
After the underlayment is placed a pre bent metal valley lining is installed.
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 metal lining can be made of any.
Again choosing the easy way out we opted to build blind valleys aka california valleys where one.
Open valley shingle installation.
An open valley relies on metal flashing for protection.
The metal is usually pre painted to best complement the shingles color blend.
After installing the rafters we still had to extend the porch roof back over the shed roof creating a valley on either side.
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.
Shingle the other side of the valley the same way.
There are two common methods for completing the flashing of a valley in a shingle roof system.
First clean the debris out of the valley including sawdust nails and whatever else is in there.
Roofing shingles are installed then cut and sealed where they overlap the metal channel.
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.
Also different architectural styles will use the same type of roof.
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.
One of the details that varies between homes is the method of flashing the valley areas of the roof.
In this video we ll flash the valley.
Stop nailing 6 inches from the center.
Roof valleys are like gutters with a steep pitch.
To understand what makes a valley either closed or open it is important to understand how a valley is constructed.
The gable roof on the porch addition was framed with a dropped structural ridge supporting the common rafters above.
For an open valley a sheet of metal usually steel sometimes copper is fastened to the roof deck.
When compared to a closed valley and open valley adds an additional layer of lining.