Open Or Closed Roof Valley Better

The shingles will act as the valley lining and will protect the roof deck and underlayment against water run off.

Open or closed roof valley better.

I m leaning towards an open metal valley but i ve had contractors disagree saying that the metal expands and contracts too much. After covering the roof with underlayment they ll then install a pre bent metal valley. Open valleys on the other hand leave the metal exposed which may be more pleasing to the eye especially if copper is used as the valley lining. The open valley looks like each plane of the roof was cut in separate and the eye is drawn to the separation.

It is important to remember that a closed valley conceals the valley lining and allows the planes of the roof to blend together. The only type of valley that is unacceptable is the woven valley. 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. Open valleys may be susceptible to water backup if the cut off shingles are not properly trimmed potentially causing roof leaks.

For this reason professional roofers proudly supports the closed system of valleys. It is always a good idea to check with the manufacturer or a certified installer of the product such as ourselves. Roofers on the other hand often prefer an open valley because they feel it is more practical. The metal is usually pre painted to best complement the shingles color blend.

However a closed system simply performs better. Closed roof valleys are also more affordable as installing a metal lining costs extra. For an open valley a sheet of metal usually steel sometimes copper is fastened to the roof deck. I kind of prefer the look of the closed valley.

Although the open valley is recommended by the manufacturer closed valley is acceptable. It might cost a little more in materials around 150 500 on average depending on the home and material. When installing a closed valley the roofer will cover the roof with underlayment. And while some homeowners may prefer the aesthetics of a closed valley the heavier and thicker the shingle the less likely it is to lie flat across a joint.

Architects often prefer closed valleys to open valleys as they feel that it gives a home better architectural appeal. When installing an open valley the roofing company will add another layer of lining to the roof valley. They ll then install the shingles onto the roof deck extending them through the valley. That said an open roof valley is a good option if you want to the metal strip to serve as an architectural detail on the roof.