How To Install Valley Flashing On A Metal Roof

That flashing is left exposed so the roof has visible lines of metal running down the valley.

How to install valley flashing on a metal roof.

W type valley flashing is more rigid for handling so it stays straight and it stops waler rushing down one side of a roof from rushing back up the other side. Lay one and two tab shingles as you near the valley so full size shingles will run across the valley. The top joinery of both valleys when they meet on the same plane of roof is shown here. Snap a chalkline 2 to 3 inches past the valley center on the top layer of shingles.

Stop nailing 6 inches from the center. An open valley relies on metal flashing for protection. Shingle the other side of the valley the same way. The edge of the roof has thin metal flashing that helps water drip off the roof without damaging the home or causing a leak.

Lap successive sheets of metal flashing a minimum of 12 inches and seal laps. Install an underlayment centered in the roof valley. Install synthetic roofing underlayment or felt paper according to manufacturer specifications and then install the first piece of valley flashing. Flashing should be installed in all of the valleys.

When installing metal valley flashing there are a few things to keep in mind from cutting metal roofing to sealing the flashing. Open valley shingle installation. I have my valley custom made with water trough to help with leaking b. Recommended procedures of basic valley flashing installation.

Roof one side of the valley running the shingles across it. While some skylight manufacturers include flashing in their products sometimes roofing professionals have to create it or purchase it separately. 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. Then install a non corrosive metal valley flashing of 24 minimum width.