Tile Roof Valley Flashing

Unobstructed water flow in the valley flashing is critical.

Tile roof valley flashing.

Extend entire width of flashing completely to the bottom of the roof valley. Drip edge metal valley flashing dormer chimney and kick out flashing shed water away from the connections between roofs walls chimneys and other building assemblies this collection of 18 articles animations and videos identifies the critical roof flashing areas illustrates durable roof flashing details and shows how to flash roofs. 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.

Cut the bottom edge and fold it down over the drip edge. 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. 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. W valley metals designed for wood shakes and asphalt shingles do not prevent clogs and direct water into the roof system which can damage the underlayment and cause the roof deck and underlying structure to rot.

Should a dam develop then water may back up under the tile or shingles and end up creating a leak. Double ribs elevate tile battens above water flow area. Use roof valley cleats at intervals of 24 o c. There is less of a chance for leaves to gather in a spot in the valley and form a small water dam.

Closed valley s or open valleys. Using clips permits movement in the valley as temperatures change. The reason that many roofers like an open valley is that they feel that tree leaves and needles will more easily slide down or wash down an open valley when it rains. This can speed degradation of the underlayment and may cause rot in the battens and decking.

Make sure to cover the gap at the bottom of the raised ridge to keep bugs and ice out. A flat tile installed directly onto standard valley flashing in a closed method restricts water in the valley flashing during heavy rains and may cause it to overflow.