How To Install Valley Flashing On A Metal Roof

The top joinery of both valleys when they meet on the same plane of roof is shown here.

How to install valley flashing on a metal roof.

I have my valley custom made with water trough to help with leaking b. Then install a non corrosive metal valley flashing of 24 minimum width. While some skylight manufacturers include flashing in their products sometimes roofing professionals have to create it or purchase it separately. Lap successive sheets of metal flashing a minimum of 12 inches and seal laps.

That flashing is left exposed so the roof has visible lines of metal running down the valley. Install an underlayment centered in the roof valley. Roof one side of the valley running the shingles across it. 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.

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. Recommended procedures of basic valley flashing installation. Open valley shingle installation. Flashing should be installed in all of the valleys.

The edge of the roof has thin metal flashing that helps water drip off the roof without damaging the home or causing a leak. Installing metal flashing for your roof project is a challenging but essential step to take to ensure that the new roof remains as weatherproof and as strong as possible the following steps will explain how to install metal flashing in roof valleys. Shingle the other side of the valley the same way. Install synthetic roofing underlayment or felt paper according to manufacturer specifications and then install the first piece of valley flashing.

An open valley relies on metal flashing for protection. When installing metal valley flashing there are a few things to keep in mind from cutting metal roofing to sealing the flashing. Stop nailing 6 inches from the center. Snap a chalkline 2 to 3 inches past the valley center on the top layer of shingles.