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.
Roofing valley transition.
At the roof transition shown in.
Cut the panels from the ground instead of on the roof to avoid damaging the roof with the debris.
Take care not to place any fasteners in the exposed center area of the metal flashing.
How to seal metal roof valley.
Fold the top over the roof ridge and cut the bottom along the drip edge metal.
Best practices for sealing the metal roof valley vary based on the slope of the roof.
Apply an approximately 3 inch width of asphalt roofing cement along the sides of flashing and embed shingles in mastic clip the top corner of shingles along valleys to keep water flow toward center of valley.
If repairs are needed the contractor has to remove and then reweave multiple shingles to replace a single one.
The lower roof unavoidably slows down water drainage and when the valley is clogged a significant amount of water coming down that valley will tend to spread out and back up under the shingles.
In order to shingle this kind of roof valley a roofing professional has to install both roof faces at the same time which is quite slow.
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.
Low slope roofs slope less than 3 12 use tape sealant between the valley trim and the panel.