No one of this affirmat.
Open cut roof valley.
However it is said that provided the rest of the roofing shingles were properly installed and are performing properly open valleys will perform better over time than closed valleys.
I m trying to decide on the best way to do the valleys open metal valleys or closed cut ones.
A roof using the open valley style involves placing a v or w shaped piece of metal usually galvanized or sometimes copper in the seam of the valley and then covered with a base sheet such as 30lb.
See our discussion of alternative flashing materials found.
From the stepped off main part of the roof run shingles into the valley and cut them square from where the bottom corner intersects with the shingles nailed along the valley line.
Open valleys may be susceptible to water backup if the cut off shingles are not properly trimmed potentially causing roof leaks.
The rest of the nails go in the nailing strip.
I m in a mixed humid climate zone 4a.
In this video i show you how i do the valleys on a shingle roof.
An economical version uses two layers of roll roofing for the lining which should last as long as an asphalt roof.
The cut edge then is sealed with roof cement.
Can t afford standing seam metal though so it will be mid grade architectural asphalt shingles installed with meticulous detail.
At flashing wall details.
That flashing is left exposed so the roof has visible lines of metal running down the valley.
With a heavy gauge noncorrosive metal lining open valleys are the most durable valley and the most costly.
An open valley relies on metal flashing for protection.
And either an organic or modified underlayment depending on whether tiles or shingles are being.
Roofing shingles are installed then cut and sealed where they overlap the metal channel.
With sheet metal protecting the lower layer of shingles the shingles on top are cut back to the line right.
A chalk line is then used to strike a line from the top of the valley to the bottom of the valley.
With an open valley a strip of metal will be visible on the roof wherever two opposing roof planes meet.
The shingles are then cut out of the valley area opening the surface of the valley lining to water run off and the environment.
For an open valley a sheet of metal usually steel sometimes copper is fastened to the roof deck.
The metal is usually pre painted to best complement the shingles color blend.
The seam where the two planes of roofing meet are aesthetically woven together to form an interlaced design which creates a seam that matches the contours of the roof.
One nail goes into the top section of the shingle where it covers the valley metal.
Roof is 5 12 slope with a couple of valleys.
Open valley shingle installation.
I want my roof to be as leak proof and long lasting as possible.
When all the shingles are installed to the guide line the cutline is resnapped left.
