Open Valley Roof Flashing

Lile points out that valleys lined with roll roofing are not as durable.

Open valley roof flashing.

Step 9 cut corners and apply cement dub cut the top layer shingles see step 4 in open metal valley above. When properly installed w valley flashing will reliably channel run off water down the roof and into the gutter. In comparison to a closed valley an open valley adds another layer of lining into the valley. Cut bottom of flashing so the entire width of the valley flashing extends approximately 1 2 to 3 4 over the fascia trim board along eaves the following photos illustrate removal and replacement of a closed cut valley with new open metal valley.

Roof valleys are like gutters with a steep pitch but the stakes are higher for valleys than they are for gutters in a previous video we covered how to flash roof edges before shingling. Pros and cons of a closed valley roof architects often prefer closed valleys to open valleys as they feel that it gives a home better architectural appeal. That flashing is left exposed so the roof has visible lines of metal running down the valley. Flashing a humpy old roof valley requires a little give and take and a backup plan.

To splice the pieces add roofing cement to the lower piece and install the upper piece with at least a six inch overlap. Slip a piece of sheet metal flashing under the top layer of shingles to protect the bottom layer in the valley while you cut the shingles with a hook blade. Be sure to check local building codes to ensure you have the proper width for your application. After the self adhering underlayment is installed across the valley a pre bent metal valley lining is installed.

This valley flashing material can be manufactured from any metal that will resist the effects of weather acid rain and other contaminants. Nrca lile recommends that roof valley flashing metal for open roof valleys should be 26 gauge 0 45mm galvanized steel or equivalent noncorrosive nonstaining metal. 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 is used. An open valley relies on metal flashing for protection.

How to flash an open valley with w type valley metal. Extend entire width of flashing completely to the bottom of the roof valley.