Open Metal Valley Roofing

The following photos illustrate removal and replacement of a closed cut valley with new open metal valley shingles being removed in closed cut valley.

Open metal valley roofing.

First clean the debris out of the valley including sawdust nails and whatever else is in there. This metal lining can be made of any type of metal that is resistant to the effects of weather acid rain or other contaminants. This valley flashing material can be manufactured from any metal that will resist the effects of weather acid rain and other contaminants. Installation instructions often call for avoiding fasteners except clips or through slots but roof penetrations and many flashings like drip gable and end wall flashings are fastened directly and seemingly do just fine.

If the metal expands and contracts you could get some minor oil canning but nothing that effects the integrity of the valley. Entire width of new metal flashing properly extends over fascia at bottom of roof. I m sure they are there for a good reason. Open valley when compared to a closed valley and open valley adds an additional layer of lining.

After the self adhering underlayment is installed across the valley a pre bent metal valley lining is installed. Metal roofing and flashing details are a bit funny that way. An open metal lined valley properly installed is functionally better long term. After the underlayment is placed a pre bent metal valley lining is installed.

From a more opinionated viewpoint an open metal lined valley has a cleaner and more appealing look. With a clean valley you can lay down some peel and stick roofing membrane. For an open valley a sheet of metal usually steel sometimes copper is fastened to the roof deck. I ve seen heater cables installed over metal valleys.

In a closed valley shingles wrap from one side of the valley to another. In comparison to a closed valley an open valley adds another layer of lining into the valley. All shingles removed from closed cut valley. The metal is usually pre painted to best complement the shingles color blend.

Fold the top over the roof ridge and cut the bottom along the drip edge metal. Roof mastic applied along sides of valley flashing. Roofing shingles are installed then cut and sealed where they overlap the metal channel.