What Is A Roof Valley? (Types, Materials & Benefits!)
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What Is a Roof Valley (Types, Materials & Benefits!)

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Posted By: Roof Troopers

roof valley on older rooftop

Most homeowners aren’t contractors. That means most homeowners probably can’t tell you what a roof valley is or why it exists. While there’s no shame in not knowing what the components of your roof are, it is essential to ensure that your roof’s overall design is sound and made from the right materials — especially when you have asphalt shingles.

With all the different types of roof valleys, it can be a bit confusing to determine whether your existing roofing system is actually right for your home. The same goes for when it comes time to choose a new roof valley.

In this article, we’ll cover everything you need to know about roof valleys, including::

  • The different types
  • Materials
  • Their benefits 

Keep reading to learn more!

What Is a Roof Valley and What Does it Do?

roof valley on metal roof

Simply put, a roof valley is when two roof facets (facing surfaces) form a slope from an interior angle. You can think of it as a kind of V-shape, and you’d be able to point it out immediately just by looking.

The whole purpose of roof valleys is to allow water and any debris in the water to flow down and off your roof to keep it from pooling. There are essentially two basic types of roof valleys:

  • Closed roof valley
  • Open roof valley

The names are determined by how the roofing material is used to adhere them. 

Closed Roof Valley

Closed roof valleys are assembled by installing the roof shingles onto the roof deck in a way that extends over the area where the two opposing roof planes meet. This allows the roof shingles to cover or “close” the valley area, so the roof’s underlayment material isn’t exposed. With a closed roof valley, the asphalt shingles serve as both a lining and a surface protectant against water.

Open Roof Valley

Open roof valleys, on the other hand, are installed using an additional layer of lining in the valley area. The self-adhering underlayment is installed across the valley first, then a pre-vent valley lining (also referred to as flashing material) is installed. 

The material used for the flashing is typically a metal that’s resistant to the effects of weather, acid rain, and other contaminants. This would include aluminum, copper, and galvanized steel.

For the installation, the shingles are placed over the roof deck so they extend into the valley but do not run entirely over it. Instead, they come up to the center of the valley — which is where the metal flashing is placed — so that the flashing remains exposed. 

Open valleys tend to perform better in climates that see a lot of snow and ice as metal materials are excellent for shedding snow and debris.

What Are the 3 Different Types of Roof Valleys?

There are also several sub-types of roof valleys that homeowners can choose from:

  • Cut
  • Woven
  • Exposed Metal flashing

Keep in mind that while each type will vary in cost, appearance, and functionality, it’s important to consider what your home needs versus what you want aesthetically.

1) Cut Roof Valley

roof valley on shingle rooftop

The cut roof valley is arguably the most popular type installed on roofing systems with asphalt shingles. Aesthetically, it looks good, and most roofing contractors believe it works best to slough off excess water from your roof and into your gutters. 

As for the design of the cut valley, the shingles from one roof slope will extend a few extra feet to overlap the adjacent slope. From there, the shingles from the adjacent slope are cut parallel and trimmed to just come up to the center of the valley. This overlap provides a seamless appearance throughout the entire roof, making it look even and uniform.

Additionally, when a cut valley is well-installed, the top corner of the shingles will be clipped. This ensures that any cross-wash is rerouted back into the valley for proper drainage. 

2) Woven Roof Valley

With woven roof valleys, the shingles are woven together throughout the valley. This is very similar to that of the cut roof valley type, only the design gives a more obvious woven appearance as the shingles are installed on opposing roof planes at the same time and strategically overlapped at the inversion of the valley.

This also provides a seamless aesthetic as well as superior ice and snow shedding in the winter.

3) Exposed Metal Flashing

Exposed metal flashing is essentially the same as an open roof valley. The only factor that separates it from the rest is that exposed metal works for all types of shingle materials, not just asphalt. 

Exposed metal valleys are rich in their aesthetic and come with the price to match. You can choose from a variety of colors of metal to complement your shingle type and color, and they tend to outperform and last longer than the closed valley types. 

How to Choose a Roof Valley for Your Home

If you’re in need of a new roofing system, roof valleys will be a crucial part of determining the type of materials and layout. As mentioned earlier, choosing a roof valley comes down to three factors — cost, aesthetics, and functionality. The most important factor to focus on would be functionality, as you’ll need roof valleys that perform well in the type of climate you live in. 

The best thing you can do is speak with your local roofing experts. Not only will they be able to advise you on the best type of roof valleys for your home, but they’ll also be able to work with your budget to ensure you get the roofing system your home needs without skimping on quality. 

The roofing experts at Roof Troopers can give you an honest evaluation for your next roofing project. We also offer financing plans and excellent warranties to ensure you get the roof you need now — not later. Give us a call today to learn more about our services and to schedule a no-obligation evaluation. We’ll also provide you with a free estimate!


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