Open Vs Closed Roof Valley

We don t normally offer this line although it is available.

Open vs closed roof valley.

According to long time iko sales representative jeff tessaro closed valleys for residential construction have been popular since he was a roofing contractor in the late 90 s. It s all a matter of determining what you re looking for in a roof. Closed valleys are very vulnerable to mechanical damage. After the self adhering underlayment is installed across the valley a pre bent metal valley lining is installed.

This metal lining can be made of any type of metal that is resistant to the effects of weather acid rain or other contaminants. For a closed valley shingles are installed across the joint where planes intersect. It is always a good idea to check with the manufacturer or a certified installer of the product such as ourselves. Although the open valley is recommended by the manufacturer closed valley is acceptable.

When installing a new roof one of the decisions you have to make as a home or building owner is whether or not you want to have open or closed valleys. With each new course roofing shingles continue up the valley. Open valleys can help your roof shed ice and water more efficiently but closed valleys are faster easier and generally cheaper to install. To make it easier on you we have included some photos of open and closed valleys in this post so that you can see the difference.

Once the shingles are installed they don t run through the valley area. The only type of valley that is unacceptable is the woven valley. When compared to a closed valley and open valley adds an additional layer of lining. If you have a shingled roof as most torontonians with a sloped roof tend to have then you will have one of two kinds of valleys on your home.

Open roof valley this is almost the same as the closed roof valley method except a pre bent metal valley lining is installed instead of a secondary roof underlayment. This leaves a metal strip or line on the surface of the roof that serves as the valley line. This valley flashing material can be manufactured from any metal that will resist the effects of weather acid rain and other contaminants. You are probably wondering what the heck that means.

The closed variation is a flashing that has been completely covered with shingles while in the open variation will have the flashing completely exposed to the elements. In comparison to a closed valley an open valley adds another layer of lining into the valley. Meanwhile on an open valley roof the metal lining that prevents water from seeping into the underlayers is left exposed. After the underlayment is placed a pre bent metal valley lining is installed.