How To Install Valley Flashing On A Metal Roof

Open valley shingle installation.

How to install valley flashing on a metal roof.

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. Metal valley trim also known as metal valley flashing is beneficial because it drains water away from the structure of your metal building which helps prevent moisture damage. Recommended procedures of basic valley flashing installation. Snap a chalkline 2 to 3 inches past the valley center on the top layer of shingles.

An open valley relies on metal flashing for protection. Roof one side of the valley running the shingles across it. Flashing should be installed in all of the valleys. Lap successive sheets of metal flashing a minimum of 12 inches and seal laps.

When installing metal valley flashing there are a few things to keep in mind from cutting metal roofing to sealing the flashing. Shingle the other side of the valley the same way. Lay one and two tab shingles as you near the valley so full size shingles will run across the valley. Install synthetic roofing underlayment or felt paper according to manufacturer specifications and then install the first piece of valley flashing.

I have my valley custom made with water trough to help with leaking b. Stop nailing 6 inches from the center. 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. That flashing is left exposed so the roof has visible lines of metal running down the valley.

The edge of the roof has thin metal flashing that helps water drip off the roof without damaging the home or causing a leak. Install an underlayment centered in the roof valley. 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. The top joinery of both valleys when they meet on the same plane of roof is shown here.