Dead Man’s Valleys on Roofs: Pros, Cons, and Solutions

A "Dead Man's Valley" is a term used in roofing to describe a specific area where three roof planes meet at an angle, creating a low point that directs water runoff to a highly concentrated area. These valleys are often considered problematic in roofing systems due to their potential to cause water damage issues. In this article, we’ll explore the pros and cons of dead man's valleys, how they function, and the potential solutions to manage the water flow more effectively.

What Is a Dead Man’s Valley?

A Dead Man's Valley is formed when three roof slopes and two roof valleys meet, typically at an angle of around 90 degrees or less, creating a trough or "valley"  that meets together at the bottom of a roof. A Dead Man's Valley ALWAYS ends about 2-6 feet above the eavestrough and then dumps all the water from this area down another roof into a section of eavestrough that is about 2-3' in length. See pictures below.

You can see from the above picture that more than half the front of this roof ends in a small triangle area that then dumps all that water into a very small section of 5" eavestrough. There is NO WAY this 5" eavestrough can handle the amount of water coming from this section of roof!!

Dead Man's Valleys are commonly found in homes with complex designs or steep roof pitches. The term "dead man's valley" refers to how the water gets trapped in a narrow channel, leading to potential drainage issues.

These valleys are typically seen in homes with steep-pitched roofs or where multiple rooflines converge. The water from these roofs tends to collect and flow toward one or two small sections of guttering, which, if not properly managed, can easily become overwhelmed.

Pros of Dead Man's Valleys

While Dead Man’s Valleys are often associated with drainage problems, they are not without their benefits. Here are a few pros to consider:

1. Efficient Use of Space: In certain roof designs, these valleys help to maximize the use of roof space by allowing water to flow to a centralized area, which can be convenient in terms of roof layout and design.

2. Aesthetic Appeal: A well-designed valley can contribute to the visual appeal of the roof, giving it a more structured, symmetrical appearance. This can be particularly desirable in architectural styles that emphasize sharp angles or intricate roofing systems.

Cons of Dead Man's Valleys

Despite these advantages, the cons far outweigh the pros when it comes to water management. Here are the primary drawbacks:

1. Overwhelmed Eavestroughs: The most significant downside of Dead Man’s Valleys is that they channel a HUGE volume of water into a small area. In most cases, the runoff from both valleys flow into a single eavestrough. If the eavestrough is too small or clogged, the water overflows, leading to water damage to the roof, walls, and foundation.

2. Water Pooling and Backups: In many cases, the water runoff from Dead Man’s Valleys can pool in the gutter, causing backups that lead to leaks or ice dams in colder climates. This pooling water can also damage the gutter system over time.

3. Risk of Roof Damage: Excessive water buildup in these valleys can also lead to roof leaks. As water collects in the valley, it can seep into the roofing material, causing the underlayment to weaken and leading to possible structural damage. This is especially concerning in areas with heavy rainfall or snow.

4. Clogged Gutters: Leaves, debris, and other materials can easily accumulate in the valley, further exacerbating drainage issues. Roof valleys are ALWAYS debris collection sites. As the water runoff from the roof concentrates in one area, it carries with it debris that can clog gutters and downspouts.

Solutions for Managing Water in Dead Man's Valleys

To address the problems associated with Dead Man's Valleys, there are a range of solutions to improve water drainage and protect their homes from water damage.

1. Install a 6-Inch Eavestrough

One of the most straightforward solutions to the issue of concentrated water runoff in Dead Man’s Valleys is to install a 6-inch eavestrough with a 3x4 downpipe along with a splash guard. Traditional 5-inch gutters are always insufficient to handle the volume of water funneled into them from a valley, especially during heavy rainfall.

By upgrading to a larger 6-inch eavestrough, the gutter system can accommodate more water, reducing the likelihood of overflow and water damage. 

2. Install a French Drain

In some cases, it may be beneficial to address the water overflow problem on the landscape where the water overflows the eavestrough and falls to the ground. Installing a French drain under the ground can help channel excess water away from the foundation of the home and prevent water from pooling near the foundation.

A French drain typically consists of a perforated pipe surrounded by gravel or rock, which helps to collect and redirect water. The drain can be routed to a lower-lying area of the yard or to a designated drainage system, ensuring that water does not accumulate around the foundation.

3. Install a Splash Guard

Another option for preventing water from seeping into the roof structure is to install a splash guard. This metal flashing is will help stop the water from over flowing in moderate to light rain

4. Never install gutter protection on the eavestrough below the Dead Mans Valley. 

Anyone who knows me knows I am a big fan of gutter protection and I believe it should be installed on every job. HOWEVER, the eavestrough directly below the Dead Man's Valley should never have it. There is too much water going to this area and it can not assimilate the water fast enough.

5. Meticulously maintain the eavestrough below the Dead Man's Valley.

Making sure there is no debris or obstruction is this eavestrough should be a monthly occurrence! Seriously! This is a must!!!!

Conclusion

Dead Man’s Valleys are a common and always problematic designs of many roofs. While they can help to maximize roof space and add aesthetic appeal, they tend to channel large amounts of water into small, concentrated areas, which overwhelm eavestroughs and lead to water damage. By installing a 6-inch eavestrough, incorporating a French drain, and maintaining proper gutter care, homeowners can manage the flow of water and prevent costly damage to their property. With a plan and proper care, you can protect your home from the risks associated with Dead Man’s Valleys while maintaining the aesthetic integrity of your home.

If you would like a quote for eavestrough, fascia, soffit, siding or gutter protection give us a call at 905-966-2564 or visit our website at www.theeavestroughcompany.com