Roof leak? Call us.(503) 925-0125

The Proper Way to Deal With a Dead Valley Roof

Posted May 10, 2022 by Jerry Becker
Let Us Help

Almost every roof features a valley or a spot where two sections of the roof intersect. Water may build up here, but it usually doesn’t pose too much of a problem as the water will easily drain away.

However, have you ever heard of a dead valley?

A dead valley happens when a very flat valley makes it virtually impossible for excess water to drain out. It can also happen when a downsloping section of your roof intersects with an exterior wall. 

Without taking the proper care, a dead valley can result in leaks and other serious damage to your roof. Luckily, we’ve assembled this guide to let you know how you can easily fix a dead valley roof before problems arise. 

Are Dead Valleys a Problem?

A roof dead valley can become a serious problem. This is because they collect not only rainwater, but snow, leaves, and other debris, as well. This collection of substances can wear away at your roof, causing it to decay and leakages to occur.

However, dead valleys don’t ever have to become a problem in the first place. There are easily fixable, without extensive roof repair or replacement. 

To make sure your dead valley roof never becomes a problem, there are some useful solutions you can try, including:

Solution #1: Custom-Made Metal Pan

A custom-made metal pan is probably the best solution for roof problems such as a dead valley. These are especially useful in dead valley corners, where water flows into the corner instead of off the roof. 

Installing a metal pan can help to seal the leakage and slope the water off of the roof. Having these pans custom-made ensures that the seal will be perfect, preventing any water from spilling through. 

However, this can be a relatively costly and extensive process and is not ideal for every homeowner. 

Solution #2: Ice and Water Shield

Even in places with warmer weather, an ice and water membrane can help to keep water from damaging your roof. Made from a sticky substance that adheres to the plywood underneath your shingles, these protective membranes protect the integrity of your home. 

Getting a professionally made metal shield is far more effective than homemade caulked or glued “flashings.” These are not as durable and can need more frequent repairs to remain effective. 

The ice and water shield is one of our most popular membranes for any underlying roofing protection. However, it is not the only solution. 

Solution #3: Modified Bitumen

High-quality modified bitumen is also sometimes used in certain areas to help avoid leaks or seepage and improve water flow. Modified bitumen is an asphalt-based roofing system that offers several layers to provide leak resistance. 

Modified bitumen requires minimal roof maintenance. It can be used across the entire roof or to solve dead valleys in certain sections of the roof, making it an incredibly versatile solution for this common roofing problem. 

This is one of the most bulletproof solutions for keeping leaks at bay, as the water is totally unable to enter the home and affect the roof’s integrity.


PVC and TPO are other materials that are commonly used to create leak-resistant membranes. 

TPO stands for thermoplastic polyolefin and is a white single-ply sheet. Because it is white, it not only helps water flow off the roof but also helps to reflect heat. This cools down the room inside while protecting it from leakage.

PVC works much the same way. However, PVC is a bit more durable and inflexible than TPO. Determining which type will work for you depends on a variety of factors, and is best decided with the help of a professional.

It is important that any membrane roofing you get comes from a reputable supplier, as they can vary drastically in terms of quality.

When Dead Valleys Become a Problem

Even though there are solutions to fix a dead valley, they can still become a problem if not addressed early enough, or if addressed in the wrong way. Failing to fix a dead valley can drastically reduce the lifespan of your roof.

One “solution” that is frequently used by builders and roofs is to run down a bunch of shingles and some felt paper in an area with little to no slope.

Despite their expectations, this won’t last very long. In fact, you’ll likely see a leak in this spot within 3 to 5 years with a faulty solution like this.

False solutions such as this can cause serious problems. These include:

Pooling of Water and Debris

Obviously, pooled water is the most common cause of leakages in residential and commercial roofing. But that’s not the only negative effect it can have. 

In fact, pooled water and debris is also a huge attractant of various kinds of pests. Mosquitos especially love ponds of water on your roof, as they make for perfect breeding grounds. Plus, as this water seeps through the roof, other pests such as cockroaches and termites are more likely to begin nesting inside your home. 

Other animals, such as raccoons or rats, may also stop by this pooled water. It’s a great place for them to get a drink, and the debris that collects can be used in nest building for a variety of creatures. 

So, aside from leading to potentially costly repairs, pooled water can also create whole ecosystems that are better kept away from the home.

Ice Dams And Ice Damage

Ice dams can cause some serious damage to the home, even in places where water is seemingly able to flow. Ice dams happen when a ridge of ice forms along the edge of the roof, preventing melting snow from appropriately draining off the side. 

Once again, ice dams are a major leak risk. They can also cause the build-up of mold and mildew. Additionally, when ice freezes and melts, it can cause untold physical damages, such as major cracking along the roof surface.

Ice dams can cause dead valleys where there previously were none and make existing dead valleys worse. That’s why it’s best to keep your home protected from the potential of ice dams with the proper water and ice protections laid in place.  

Moss and Rot

Everyone loves a rooftop garden. But unwanted vegetation growth…not so much. Vegetation growth such as moss, algae, and weeds can also damage the integrity of your roof and are more likely to grow where there is standing water. 

When unwanted vegetation starts to grow, the roots can make their way into any small crevice of the roof and create a really big problem. In fact, these roots can rip apart any membranes on or under your roof. 

They can also create a negative feedback loop by pooling even more water and attracting even more pests to your home. 

Excessive Leaks

Of course, leaks are the problem that everyone fears when it comes to dead valleys. If you’ve started to notice more and more leaks coming from your roof, you may have a dead valley that you’re unaware of. 

In fact, most homeowners don’t even know they have a dead valley roof until a problem, such as a leak, presents itself. The good news is, just because you’ve noticed a leak doesn’t mean it’s too late to fix your dead valley problem.

Membranes and other solutions can be installed during roof repairs to help protect your roof from water pooling and unnecessary damages. 

How to Fix a Dead Valley

Dead valley roofs are best fixed by professionals. In fact, this is one project that isn’t really safe or effective to DIY. When it comes to protecting your roof, you want to make sure the job is done right.

Any roof repairs, for that matter, should not be an at-home project. They can not only be dangerous missions, but they can also end up being costly and ineffective if you’re not a professional. In fact, DIY roof repair and dead valley repair are oftentimes more costly than simply hiring the pros. 

Professionals also have the right safety equipment and tools to get the job done correctly and in a timely manner. The professionals will also make sure you have top-of-the-line parts and products. This is especially important when purchasing a roof membrane, such as a PVC or TPO membrane.

Quality can vary drastically when it comes to dead valley repair and other standard roof repairs. That’s why working with our professional team is your best bet for getting cost-efficient, effective roof maintenance. 

Don’t Let a Dead Valley Get You Down

If you suspect or know that you may have a dead valley, the time to act is now. Tackling dead valley roofs before they can become a larger issue is the safest course of action. 

Contact our team for a consultation. Our experts can answer any questions you may have about protecting your roof, your home, and your family. 


Previous Article
Next Article

Call Roof Life of Oregon Today

If you’re looking for a team that is as knowledgeable as they are kind and proactive, Roof Life of Oregon is the choice for you. Contact us today to experience the difference for yourself.

We’re Here to Help You

A healthy and properly functioning roof, free of moss and debris is also appealing and a source of homeowner pride.

Get a free quote for an inspection today.