Roof Valley Flashing Detail

Flashing against a vertical sidewall shall be by the step flashing method.

Roof valley flashing detail.

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. Valley flashings are custom fabricated to any measurements and angles and usually measure 10 in length but can also be we can also match any profile. One of the details that varies between homes is the method of flashing the valley areas of the roof. To understand what makes a valley either closed or open it is important to understand how a valley is constructed.

Using clips permits movement in the valley as temperatures change. Special pricing available for large quantities. 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. Use roof valley cleats at intervals of 24 o c.

Closed valley s or open valleys. Edge flashing and starter strip roofs peel off from the edges so it is critical to hold them tight with the roof deck sealed on the outside we turn to flashing the edges with metal and membranes metal drip edge flashing details roofing wrb flashing. An open valley relies on metal flashing for protection. Be sure to check local building codes to ensure you have the proper width for your application.

The flashing shall be a minimum of 4 inches 102 mm high and 4 inches 102 mm wide. When properly installed w valley flashing will reliably channel run off water down the roof and into the gutter. Cut the bottom edge and fold it down over the drip edge. At the end of the vertical sidewall the step flashing shall be turned out in a manner that directs water away from the wall and onto the roof and or gutter.

Make sure to cover the gap at the bottom of the raised ridge to keep bugs and ice out. 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. Cad details document name pdf dwg download all cad construction details 37 1 mb 3 4 mb mc01 identification of roof areas 694 kb 167 kb mc01a single layer underlayment 678 kb 302 kb mc01b double layer underlayment 711 kb 322 kb mc02 vent pipe flashing 626 kb 349 kb mc03 valley. Riverside provides roof valley flashing for general contractors roofers and do it yourself home owners.

Extend entire width of flashing completely to the bottom of the roof valley. That flashing is left exposed so the roof has visible lines of metal running down the valley. The installer fabricates simple clips or valley flashing cleats whose bent edge interlocks with the folded over or hemmed edges of the metal roof valley flashing to secure the valley to the roof deck.