Roof Valley Pointing
I suspect it has never been done properly each of the 3 times it has been pointed.
Roof valley pointing. The valley area of a roof the straight lines formed when two different planes of the roof meet is a critical area that handles a tremendous amount of water run off. This is how i cement roof tiles pointing the verge in with two coats of cement the cement i use has black dye mix in it to help match the roof tiles in colo. Sheathing blocking is added along the valley and the sheathing pieced in for both roof planes. Never try and work on a roof from a ladder as a.
Use roof valley cleats at intervals of 24 o c. Woven closed cut and open. Water collects in a valley to flow off the roof. Using clips permits movement in the valley as temperatures change.
I had it repointed again in october 2014 and it has fallen out again from under the roof tiles. I had it repointed but it fell out again after another year. The installer fabricates simple clips or valley flashing cleats whose bent edge interlocks with the folded over or hemmed edges of the metal roof valley flashing to secure the valley to the roof deck. At the low end of the valley the subfascias of the two roofs are mitered with a block filling in the roof framing.
The reason why the roof valley is such a sensitive area has to do with all the rainwater and or melting snow that accumulates and flows through the valley on its way into the gutters. A roof valley is very prone to leaks especially if you have an older roof. Valleys are typically found where gable dormer roofs meet the main roof or when a house has angled wings or additions where two roof sections in different planes meet. A roof valley is formed where two roof slopes meet.
To transition the eaves the horizontal fascia extends to the last rafter tail and a vertical return finishes the transition. The original roof ridges and pointing built 1990 are fine but the pointing in the more recent valleys is crumbling and falling into gutters. This video shows how to repoint a lead roof valley. Essentially there are three main ways to shingle a roof valley.
Your choice of valley installation method is critical because when improperly installed valleys are risks for serious leaks. I had my roof retiled about 6 years ago.