Dec
09
2013
Valley Flashing | Two valleys run together
- Category: Roofing How To
- Written by Dennis Crookshanks
This is an example of two roof valleys that drain three roofing areas into one drain and downspout. This is an area where most roofing companies are hard pressed to properly install roofing in a water tight manner. 
Valley before with tarred over ice guard. Most roofers will rely on a combination of ice and water shield and caulking, or tar, when flashing a roof area that holds water, such as these converging valleys. Other roof areas, such as valleys that run into walls or chimneys in the middle of a valley are also subject to the ice guard and tar/caulking treatment.
Original drain hole covered with sheet metal.
This particular valley originally had a drain and downspout placed in the center of the valley pocket and drained through the soffit roof overhang. The previous roofers covered over that drain and added a short gutter and downspout at the edge of the roof. Destroying the architectural detail and smooth lines of the roof edge.
Repairing the old roof leaks. To repair the roof leaks, the existing shingles were removed about 3' above the valley pocket area. The ice and water shield and tar was removed and the water damaged wood replaced. The roof drain was uncovered to restore the original detail of running the drain through the soffit overhang.
New copper sheet metal flashing.
New copper sheet metal flashing was then fabricated to fit the valley pocket. Separate panels were formed to fit the rolled eave edges and the interior of the valley. A new drain outlet runs through the soffit and drains into new copper downspouts. The front of the valley pocket has a raised lip to prevent rain water running over the roof edge.
This copper flashing installation is installed with traditional roof flashing techniques. The copper panels are folded together at the edges and soldered for a permanent water tight installation that will last for a lifetime. There is no need for ice and water shield or caulking. When it comes time to replace the roofing, the roof shingles can be removed and replaced while retaining the copper flashing. And there is no need for a short tacked on section of gutter to ruin the look of the house.
