When it comes to residential roofing in Missouri, homeowners often focus on visible choices like shingle color or gutter style. However, one of the most crucial—yet often overlooked—components of your roof is the valley system. That’s where rainwater travels the most, making valleys a key player in your roof’s durability and performance.
At Emmendorfer Exteriors, we specialize in roofing solutions that balance function, style, and longevity. In this guide, we’ll break down the pros and cons of open vs. closed valleys during roof valley installation, helping homeowners in Union, Washington, Festus, and beyond make informed decisions.
What Is a Roof Valley?
A roof valley is the area where two roof slopes meet. Because of its design, it’s the primary channel for directing rain and melting snow off your roof. The performance of your valley system can make or break your roof’s resistance to water damage.
During roof valley installation, homeowners can choose between two primary styles: open valleys and closed valleys. Each comes with its own advantages and drawbacks depending on budget, roof pitch, climate, and aesthetics.
Open Roof Valleys: Overview
In an open roof valley installation, a sheet of metal—usually aluminum, steel, or copper—is installed along the valley to form a visible channel for water runoff. Shingles are cut back a few inches on each side, exposing the metal beneath.
Pros of Open Valleys
- Superior drainage: The metal channel prevents water from backing up and helps snow melt faster
- Easy maintenance: Since the metal is visible, damage and debris are easier to spot and address
- Durability: Metal valleys can outlast shingles and resist decay, especially in high-moisture areas
- Ideal for steep pitches: Open valleys perform well on complex rooflines with heavy runoff
Cons of Open Valleys
- More visible: Some homeowners prefer a more seamless aesthetic
- Higher initial cost: Metal flashing and additional labor may increase upfront expenses
- Potential for debris accumulation: Leaves and twigs can collect in the valley and must be cleared periodically
Closed Roof Valleys: Overview
Closed valleys, on the other hand, are formed by weaving or cutting shingles across the valley so that the metal underneath is not visible. This style is more common in traditional residential roofs.
Pros of Closed Valleys
- Cleaner appearance: The seamless look can be more visually appealing, especially on modern homes
- Lower upfront cost: No need for extra flashing materials
- Popular with builders: Many home builders default to this option for simplicity and uniformity
Cons of Closed Valleys
- Less efficient drainage: Shingles covering the valley can slow water runoff
- More prone to wear: Shingles in valleys face heavy water flow and can wear out faster
- Harder to inspect: Issues like leaks or granule loss may go unnoticed until damage is significant
Which Valley Type Is Right for Missouri Homes?
Missouri weather brings heavy rainfall, snow, and freeze-thaw cycles—all of which put pressure on your roofing system. That’s why the right choice in roof valley installation isn’t about trends; it’s about performance.
For homes in Union, Festus, or Eureka with mature trees and higher precipitation, open valleys may be a smarter long-term investment. On the other hand, closed valleys can work well for newer constructions in Fenton or DeSoto that prioritize curb appeal and budget.
Factors to Consider Before Roof Valley Installation
To make the right decision for your roof valley installation, consider the following:
- Roof pitch: Steep roofs benefit from open valleys for improved drainage
- Budget: Closed valleys are more cost-effective in the short term
- Aesthetics: Open valleys are visible, while closed valleys blend in
- Maintenance habits: If you’re proactive about maintenance, either option can work well
- Material compatibility: Some shingle brands perform better with specific valley styles
Common Mistakes in Roof Valley Installation
Improper roof valley installation can lead to major issues like leaks, mold growth, and structural decay. Here are mistakes to avoid:
- Improper flashing overlap: Especially in open valleys, metal flashing must be layered correctly
- Inadequate underlayment: Valleys need extra protection beneath shingles or flashing
- Over-nailing shingles: Nails driven too close to valleys can cause water penetration
- Incorrect shingle cuts: Jagged or overly wide cuts compromise water flow
At Emmendorfer Exteriors, we follow best practices on every roof valley installation to ensure long-term protection.
Maintenance Tips for Roof Valleys
Regardless of which valley system you choose, proper maintenance is key. Here’s how to protect your investment:
- Inspect valleys every spring and fall for debris or granule loss
- Keep gutters clear to support water drainage
- Trim overhanging branches to reduce leaf buildup
- Watch for signs of rust or cracking on metal in open valleys
- Schedule professional inspections after severe weather events
A well-maintained roof valley installation can extend the life of your entire roofing system.
Local Experience Matters
In areas like Valley Park and Pevely, older homes may already have a specific valley system installed. When replacing or upgrading your roof, our team at Emmendorfer Exteriors can assess your current setup and recommend whether to stay with the same style or transition to a better performing option.
We bring years of experience working with Missouri’s changing seasons, steep pitches, and historic homes. Whether you’re installing a new roof or upgrading a valley system, our knowledge ensures the right fit for your property.
Final Thoughts
When it comes to protecting your home, every component matters—including your roof’s valleys. Open and closed systems each offer distinct benefits, and the best choice for your home will depend on your priorities, budget, and maintenance style.
At Emmendorfer Exteriors, we’re here to help homeowners in Union, Washington, Herculaneum, and surrounding areas make smart, lasting choices. Contact us today to schedule your roof inspection or discuss your upcoming roof valley installation. Let’s build a system that stands strong—no matter what Missouri weather brings.
